Anyone with images or footage of the incident can send them to ukpoliceimageappeal.co.uk 
 
 Image copyright Getty Images Image caption A woman lays flowers near the scene of the attack 
 
 Image copyright Getty Images Image caption Forensic officers scour Parliament Square 
 
 Image copyright EPA Image caption A photo of PC Palmer is placed among floral tributes on Whitehall 
 
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 Have you been affected by recent events? Earlier in the day, the Amaq News agency, which is often used by the Islamic State group to broadcast propaganda, said ISIS had claimed responsibility for the attack: "A soldier for the Islamic State carried out the operation in answer to calls to target the people of coalition states." A woman aged 39 was arrested in east London 
 
 A 21-year-old woman and a 23-year-old man were arrested in Birmingham 
 
 A 26-year-old woman and three men aged 28, 27 and 26 were arrested at another address in Birmingham 
 
 A man aged 58 was arrested at an address in Birmingham 
 
 The Met Police says detectives are continuing to search a number of addresses, including one in Carmarthenshire, three in Birmingham and one in east London. In the attack on Wednesday afternoon, a man drove a car along a pavement on Westminster Bridge, knocking down pedestrians, creating panic and leaving dozens injured. Armed with a knife, he stabbed and killed unarmed police officer Keith Palmer before he was shot by armed police. Image caption (From left) PC Keith Palmer, Kurt Cochran and Aysha Frade all died in the attack 
 
 His first conviction was in November 1983 for criminal damage and his last in December 2003 for possession of a knife. Anyone with images or footage of the incident can send them to ukpoliceimageappeal.co.uk 
 
 Police have said five people remain in a critical condition in hospital and two have life-threatening injuries. "Greater clarity is now developing regarding the casualty figures as we have now collated information from the public and five hospitals - the latest figures I have are that there are currently four dead and 29 people were treated in hospital. He emerged from the vehicle and attempted to make his way into Parliament.
– Details are still trickling out about Wednesday's terror attack in London, and the BBC and the New York Times report that the attacker was identified Thursday by Metropolitan Police as 52-year Khalid Masood, who had been convicted for a series of non-terrorism-related crimes over a span of at least 20 years. A police statement says Masood also had a "number of aliases," per Newsweek. In a speech earlier Thursday before Parliament, Prime Minister Theresa May said the attacker was born in Britain (the BBC notes Masood was born in Kent) and had been on the radar of law enforcement and intelligence agencies some time ago during a probe into violent extremism, the BBC reports. "Our working assumption is that the attacker was inspired by Islamist ideology," she said, per the New York Times. However, May added that Masood (whom she didn't identify by name), who was shot dead by cops in the attack that killed three others, was a "peripheral figure" on the Islamist extremist scene and hadn't recently been under the microscope. ISIS has claimed responsibility for the attack, per the AP and the Telegraph, with a statement by the group's propaganda outlet stating that the attacker was a "soldier" of the Islamic State. Meanwhile, London Mayor Sadiq Khan posted a video statement of his own in which he noted, "Londoners will never be cowed by terrorism," per the Guardian. Khan also said, per journalist Christiane Amanpour's Twitter feed, he won't be commenting on the diss against him by Donald Trump Jr., noting, "I've been doing far more important things over the last 24 hours."