Arrests Underline Security Jitters Before Olympics The arrests of 14 people in the last week on suspicion of terrorism in Britain has underscored jitters among police and security officials as the upcoming Olympics fixes the gaze of the world - including potential aggressors - on London. Despite an overall decline in the number of people detained over terrorism since the 2005 bomb attacks which killed 52 commuters and 4 suicide bombers on London's transit network, experts say police and security officials are growing increasingly wary. Here is a look at the current terrorism threat to Britain, and the anti-terrorism laws that the U.K. will deploy to protect the Olympics: A total of 14 people have been arrested in two separate anti-terrorism operations spanning several cities in the last week. Seven were detained by police across central England on July 3-5, six have been charged with preparing an alleged terrorist attack and one released without charge. In London, police arrested seven people on July 5-7 - six are still being questioned, while a 30-year-old woman has been freed without charge. In addition to those 14, two Muslim men were arrested in late June - and later released without charge - after they were spotted canoeing on the River Lea, a branch of which runs through the Olympic site. Authorities say none of the alleged plots are linked to London's pending Olympic Games, which begin on July 27. However, many experts believe police and intelligence officials are becoming increasingly cautious as the event approaches. "The government is simply not prepared to take any risks ahead of the Olympics," said Tobias Feakin, a security expert at the Royal United Services Institute think tank. Under usual circumstances, authorities often monitor plots for weeks or months to gather evidence - rather than swoop in immediately to arrest the suspects. Outside of Northern Ireland, the number of people arrested on suspicion of terrorism offenses has fallen sharply in the past 12 months. In 2011 there were 167 arrests in England, Scotland and Wales related to terrorism offenses - the lowest figure since 2001. It compares with an average between 2002 and 2010 of 217 arrests per year. A total of 47 people were charged with a terrorism offense in 2011 - about 27 percent of those arrested, and in line with the rates for other crimes. In Northern Ireland, which collects its arrest figures separately, a total of 159 people were detained on suspicion of terrorism between April 2011 and March 2012 - 39 were eventually charged in that period, or 24 percent. Britain currently ranks the threat from international terrorism as substantial - the middle point on a five-point scale, which means intelligence agencies believe an attack is a strong possibility, but not imminent. The level was last raised to critical - the highest level - in June 2007. David Anderson, terrorism laws ombudsman for Britain's government, says the threat has "reduced significantly in recent years." However, he also warns that "recent improvements in the security situation on both sides of the Irish Sea are not irreversible."