Counter-terror officers kill two and arrest 15 suspected jihadis in Belgium and France with Europe on high alert for further attacks 
 
 A major Islamist plot to kill police officers in the street has been foiled at the eleventh hour, prosecutors have said, after counter-terror raids led to the arrest of 15 suspected jihadis in Belgium and France. 
 
 In the same series of raids, two suspected terrorists were shot dead by police and another wounded in the Belgian town of Verviers, near the German border. 
 
 Authorities said they had moved to dismantle an active terror cell spanning both European countries to avert an imminent terrorist attack aimed at police officers and buildings in Belgium. 
 
 Eric van der Sypt, a Belgian federal magistrate, said 13 suspected terrorists were arrested in Belgium overnight with a further two detained in France. Nine of the suspects were held in raids in Molenbeek, two in Brussels, one in Berchem, one in Verviers, where the shootout took place, and two in France. 
 
 Facebook Twitter Pinterest Belgian federal prosecutor Eric van der Sypt speaks to the press in Brussels. Photograph: Julien Warnand/EPA 
 
 All three Verviers gunmen were Belgian nationals and are thought to have belonged to a homegrown cell of jihadis that recently returned from Syria. Van der Sypt added that officers were still working to formally identify the two gunmen killed in the shootout. 
 
 At the address in Verviers, police found ammunition and weapons including four Kalashnikovs, several smaller firearms and explosives. Search teams also discovered several police uniforms, walkie-talkies, radios, mobile phones and false documents and a “significant amount of money”, Van der Sypt said. 
 
 In Molenbeek, police found ammunition, a knife, mobile phones and “different objects important for the investigation”. 
 
 “This operation was meant to dismantle a terrorist cell and also the logistic network behind it,” he said. “This investigation for the time being has shown that these people had intentions to kill several policemen in the street and at police [stations].” 
 
 Van der Sypt said there was no link between events in Verviers and last week’s terror attacks in Paris but revealed that an atrocity on a similar scale had been averted at the last minute. 
 
 “This operation stopped a major terrorist attack from taking place. You could say a second potential Paris has been averted,” he said. 
 
 Meanwhile, several Jewish schools in Belgium have been closed amid warnings that they could be targets for Islamist militants, while cities across the country remain on a heightened state of alert. 
 
 Facebook Twitter Pinterest The Cheider school, the only Orthodox Jewish school in the Netherlands, was closed on Friday after the anti-terrorism raids in neighbouring Belgium. Photograph: Koen Van Weel/EPA 
 
 Jewish schools in Brussels and Antwerp were closed and classes cancelled after officials said they were a “potential target” for radical Islamists, the Belgian news site Joods Actueel reported. 
 
 French and German authorities arrested at least 14 other people on Friday suspected of links to Islamic State (Isis), and the Gare de l’Est train station in Paris was evacuated after a bomb scare, with Europe on high alert for further potential terrorist attacks. 
 
 A senior Belgian counter-terrorism official, who was not named, told CNN that the alleged terror cell was believed to have received instructions from Islamic State. The US news outlet quoted a separate western intelligence source as saying that the ongoing terror threat in Europe involved up to 20 sleeper cells of between 120 to 180 people ready to strike in France, Germany, Belgium and the Netherlands. 
 
 Police sources told Belgian television stations they had resolved to launch the pre-emptive operation against the terrorist suspects a fortnight ago after bugging the homes and cars of the men who were said to have recently returned from fighting in the war in Syria. The investigation concluded that a large-scale attack was imminent, targeting police stations. 
 
 Facebook Twitter Pinterest German police guard an apartment building Perleberger Strasse in Berlin during an anti-terror operation. Photograph: Paul Zinken/Corbis 
 
 Separately, on Friday morning police in Berlin arrested two men suspected of helping to recruit for Isis in Syria. The pair were taken into custody following dawn raids on 11 residences in the German capital. Police said the men were not suspected of planning attacks in Germany. 
 
 The Paris prosecutor’s office said 12 people were arrested in anti-terrorism raids in the region, targeting people linked to the gunman who attacked a kosher supermarket in the wake of the Charlie Hebdo killings and claimed ties to Isis. 
 
 The US secretary of state, John Kerry, was in Paris on Friday to meet French leaders and deliver a speech in the Paris city hall in a visit aimed at making up for the absence of senior US officials at Sunday’s mass rally in defiance of last week’s terrorist attacks. 
 
 The head of the European Union’s police agency, Europol, warned on Friday that the large number of radicalised Islamic extremists across Europe, their lack of command structure and growing sophistication make it “extremely difficult” for law enforcement agencies to foil every terror attack. Rob Wainwright told the Associated Press that security and law enforcement agencies need to cooperate more closely. 
 
 He said the threat is evolving as cells controlled by a clear commander have been replaced by “thousands of independent actors or semi-independent terrorist suspects” who are difficult to track. 
 
 “That’s the real problem I think that the intelligence community faces right now,” he said. 
 
 The French newspaper Le Figaro reported on Friday that several French national media websites, including L’Express, Le Parisien and France Inter, were experiencing problems with serving pages. The problem was traced to a common service provider, Oxalide, which said it was investigating an “incident” with its core network, but did not yet know the cause. ||||| (CNN) European counterterrorism agencies scrambled Friday to assess the potential danger of a complex and growing terrorism threat exposed by the arrests of more than two dozen people with suspected links to Islamic extremists. 
 
 As many as 20 sleeper cells of between 120 and 180 people could be ready to strike in France, Germany, Belgium and the Netherlands, a Western intelligence source told CNN. 
 
 European Union and Middle East intelligence agencies had identified an "imminent threat" to Belgium, and possibly to the Netherlands, the source told CNN. 
 
 "There is a tremendous amount of concern over sleeper cells in Europe," said Western official with direct knowledge of the situation. 
 
 Authorities worry about a rash of copycat attacks throughout Europe, according to the official, who compared the problem to "a slow-motion car accident happening right in front of us." 
 
 Intelligence officials in Europe were trying to determine the nature of the wider threat, a senior European counterterrorism official told CNN. They were monitoring groups of men who have returned from fighting in Syria. 
 
 It is believed ISIS directed the men to return to Europe to launch attacks in retaliation for airstrikes against the terror group in Syria and Iraq, according to the official. 
 
 Overall, authorities made 17 arrests related to the Belgium threat -- 13 in Belgium and four at two locations in France. 
 
 Here are the latest developments related to the terror threat in the West: 
 
 • The suspected Islamist terrorists who had a shootout with police on Thursday in Verviers, Belgium, have ties to ISIS-linked cells in other European countries, a senior Belgian counterterrorism source told CNN's Paul Cruickshank. The two suspects who died in the shootout are believed to have fought with ISIS in Syria, the source said. 
 
 • A total of 122,000 police officers, gendarmes and military personnel are deployed across France as part of the security plan, Interior Minister Bernard Cazeneuve said. 
 
 • There does not appear to be a command-and-control element to last week's Paris attacks at the offices of Charlie Hebdo magazine and two additional locations other than a general "go forward and do something," the Western official with direct knowledge told CNN. The attacks were "highly franchised terrorism with general instructions." 
 
 • Sectarian turmoil in Yemen is bolstering al Qaeda in the Arabian Peninsula's (AQAP) local recruitment and buying it space for attacks against the West and train the next generation of bomb makers, according to one Western diplomat. 
 
 • Metropolitan Police Assistant Commissioner Mark Rowley, Britain's senior counterterrorism officer, said additional police patrols were being put in place at Jewish community centers, synagogues and schools. 
 
 • An 18-year-old woman was arrested at Stansted Airport near London on suspicion of terrorism offenses, London's Metropolitan Police said on Twitter. 
 
 • British Prime Minister David Cameron called on his country and the United States to fight the "poisonous ideology" behind the terrorist attacks that killed at least 17 people in France this month. "Britain and America both face threats to our national security from people who hate what our countries stand for and are determined to do us harm," Cameron said at a White House news conference with President Barack Obama. 
 
 • Obama promised to "do everything in our power" to assist France in its effort to combat terrorism. 
 
 • Two people suspected of involvement with the alleged terror cell in Verviers were detained trying to cross from France into Italy through the Frejus tunnel, a spokesman for Belgium's federal prosecutor's office said. 
 
 • Belgian federal prosecutor Eric Van der Sypt said 13 people were arrested in a dozen anti-terror raids . Authorities believed the "threat of a terrorist attack was very imminent." 
 
 • The suspected terror cell, which included people returning from Syria, planned to target police officers, Van der Sypt said. Police said they recovered weapons, bomb-making materials and police uniforms. 
 
 • Belgium put 150 troops on standby for anti-terror operations. 
 
 • At least a dozen people were detained in the Paris region overnight in connection with last week's shootings in Paris, the city prosecutor's office said. 
 
 • Two men in their early 40s were arrested in Berlin on suspicion of links to ISIS , police said. They did not appear to have been planning attacks. Berlin police spokesman Stefan Redlich said the investigation had started a year ago; the police operation planned several weeks ago. 
 
 • The Netherlands said it was not raising its terror threat level, currently at "substantial," the second-highest . "That means there is a realistic threat, but no concrete or specific information of an attack," said government spokesman Edmond Messchaert. 
 
 • The current level of security in Belgium will remain for at least one month and will then be evaluated to determine if it needs to be modified, the country's prime minister said late Friday. "From the time we are confronted with an increase in the threat, we went to level 3 on a scale of 4; we must mobilize the resources available," Charles Michel told CNN affiliate RTL. 
 
 Following up on Paris attacks 
 
 European counterterrorism agencies have been trying to identify and thwart potential threats after the deadly attacks in Paris last week, in which 17 people were killed. 
 
 Security services are working to track those associated with the attackers: brothers Said and Cherif Kouachi and Amedy Coulibaly. 
 
 Neetin Karasular, a suspected Belgian trafficker in weapons who met with Coulibaly's widow, Hayat Boumeddiene, is in custody, Karasular's attorney, Michel Bouchat, told CNN. 
 
 Karasular was charged with association with wrongdoers and firearm offenses, in Charleroi, Belgium. But his attorney said the arrest was not connected to the other Belgian raids. 
 
 Graphic shows the links between the Paris suspects and a wider network. 
 
 Coulibaly, who attacked a kosher supermarket in Paris last Friday, pledged allegiance to ISIS. 
 
 However, the Kouachis , the men who French authorities say carried out the deadly shooting at the offices of the French satirical magazine, are believed to have had links to AQAP , which has claimed responsibility for the shootings. 
 
 A European counterterrorism official told CNN that there were indications that ISIS leadership had directed returnees from Iraq and Syria to launch attacks in Europe in revenge for Syria and Iraq airstrikes. 
 
 The official, who cited France, the United Kingdom and Belgium as countries facing a particular threat, said counterterrorism agencies in Germany are on high alert. 
 
 Several European nations, including the United Kingdom, France, Belgium and the Netherlands, are participating in the air campaign against ISIS in Iraq.
– Yesterday's terror raids in Belgium stopped, at the last minute, a terrorist plan to kill police officers in the street, officials say. Two suspected terrorists were shot dead in the series of raids, and another 15 were arrested in Belgium and France, the Guardian reports. Authorities were working to take down what they say was an active terror cell rooted in the two countries; the two gunmen killed in Verviers—and a third one who was wounded and among those detained—are believed to have been part of a "homegrown cell of jihadists" just recently back in Europe from Syria. Police found ammo, weapons including explosives, police uniforms, communication devices, and cash; they say the terrorists' plan also targeted buildings in Belgium, and several Jewish schools have been closed after warnings they could be targets. More: The Gare de l’Est train station in Paris was also evacuated after a bomb scare today, and Europe is on high alert for potential attacks. Officials say there is no link between the Belgium raids and last week's Paris terror attacks, but one notes that "a second potential Paris has been averted" with these raids. (Another 10 suspected terrorists allegedly linked to the Charlie Hebdo attacks were arrested in Paris today.) A Western intelligence source tells CNN that as many as 180 people in as many as 20 sleeper cells are primed to attack France, Germany, Belgium, and the Netherlands. And European security services have gotten tips that ISIS may be telling Europeans who have joined up in Syria and Iraq to launch attacks on their home soil; security agencies are investigating people recently returned from those countries. Separately, Germany arrested three men suspected of being involved with ISIS, but none appear to have been planning attacks.