Islamic State (IS) has claimed responsibility for the terror attack which killed three people and injured as many as 40 others in London yesterday.Islamic State says it was responsible for the London terror attack which left three people dead in Westminster, the group`s Amaq news agency said today.Their statement said: “The perpetrator of the attacks yesterday in front of the British parliament in London is an Islamic State soldier and he carried out the operation in response to calls to target citizens of the coalition”.ISIS, which has controlled parts of Iraq and Syria in recent years, has lost territory this year to local forces in those countries supported by a US led military coalition.The terror group made an annoucement in Arabic and French.The news comes as a anti-terror officers carrying automatic weapons spearheaded the hunt for known associates of the as yet unknown `lone wolf` Islamic terrorist who brought terror to the streets of London.Night-time raids were carried out at six homes in London and Birmingham.Three people were arrested at a flat above a Persian restaurant in Hagley Road, Birmingham.Photographs from the scene show a large backpack in the hallway.The confirmation of comes after ISIS supporters celebrated the deadly terror attack with memes and photos on social media yesterday.But there was no immediate claim of responsibility from jihadist network until today.Recent posts in Telegram channels linked to ISIS, calling the attack outside the U.K. parliament “blessed”.A graphic of a burning Big Ben that reads “SOON OUR Battle On Your Land” with “London”.In a statement in the House of Commons, the Prime Minister said the attacker was a “peripheral” figure.She said that he was known to the intelligence services and had once been investigated by MI5 over concerns about violent extremism.She said: “His identity is known to the police and MI5 and when operational considerations allow, he will be publicly identified.“What I can confirm is that the man was British-born and that some years ago he was once investigated by MI5 in relation to concerns about violent extremism.“He was a peripheral figure. The case is historic. He was not part of the current intelligence picture.“There was no prior intelligence of his intent or of the plot.”There is currently no evidence any organised ISIS-orchestrated plot, and the sick murderers have a track record of claiming responsibility for any act of Islamic terrorism anywhere in the world, irrespective if whether there is any formal connection.Sky News’ Alistair Bunkall said: “Islamic State has claimed responsibility for yesterday’s attack through the Amaq News agency which is affiliated with them.MI5 are now looking into what kind of digital footprint he had - “to try and figure out who he was talking to, what inspired him,” Mr Bunkall said.Acting Deputy Commissioner Mark Rowley, the Met Police`s senior anti-terror officer, confirmed that two members of the public were killed while PC Keith Palmer, a member of the Parliamentary and Diplomatic Protection Squad was confirmed dead following the horrific attack.He added that a woman in her mid-40s named as as Aysha Frade and a man in his mid-50s who has not been named had died from their injuries after they were hit by a car on Westminster Bridge.Source: Express.co.uk