London terror attacker UK-born, was on MI5 radar

The lone attacker behind the terror attack on the UK Parliament was inspired by "Islamist terrorism" and known to Britain's security services, Prime Minister Theresa May said on Thursday. May, who addressed the Commons as the Houses of Parliament reopened in the morning, a day after a terror attack on the complex claimed four lives and injured 40 others, said Britain's message was that "we are not afraid".

She added that the attacker was British born and he was once investigated in relation to concerns about violent extremism few years ago. "We are not afraid...An act of terrorism tried to silence our democracy, but today we meet as normal," May told sombre-looking lawmakers in the packed House of Commons which reopened today with a minute's silence a day after the attack.

"It is still believed that this attacker acted alone, and the police have no reason to believe there are imminent further attacks on the public. His identity is known to the police and MI5, and when operational considerations allow, he will be publicly identified. Our working assumption is that the attacker was inspired by Islamist ideology," May said.