Terror suspect arrested, identified as Khalid Mohamed Omar Ali

A man arrested on suspicion of attempting a terror attack in Whitehall has been identified as Khalid Mohamed Omar Ali.

The 27-year-old British national, who was born overseas but grew up in Tottenham, was stopped with a rucksack containing several knives on Thursday afternoon.

Ali was arrested on suspicion of the "the commission, preparation and instigation of acts of terrorism", with three knives visible on the floor at the scene. He had allegedly been carrying them in a black rucksack emblazoned with a Union Flag and the word "London" down Whitehall, just metres from Downing Street and Parliament, where a suspected Isis supporter killed five people in a car and knife rampage last month.

Ali is understood to have been under surveillance by MI5 and the police, who said he was stopped and searched on Thursday afternoon as part of an "ongoing counter-terrorism operation". "He had been travelling on the London Underground and we understand he had exited the Tube at St James's Park station before walking in the direction of Whitehall and Number 10," a policing source told The Telegraph. "At some stage an alert went out to all the teams in the area and the order was made to pick him up." Security services told staff in Parliament that police had been tipped off by Ali's family, Sky News reported.

Neil Basu, the Deputy Assistant Commissioner Neil Basu of the Metropolitan Police said searches were carried out elsewhere in London related to the arrest, with the suspect remaining in custody.

"I want to reassure the public that our increased activity to combat terrorism over the last two years continues - both by police and security services," he added.

"Activity continues around the clock to identify and stop these threats and we are making arrests on a near daily basis." Following last month's attack in Westminster, the Metropolitan Police stepped up the number of officers on patrol at key locations in the capital, with the national terror threat level remaining at "severe". Khalid Masood, a 52-year-old Muslim convert from Kent, ploughed his car into pedestrians on Westminster Bridge, killing four people, before stabbing PC Keith Palmer to death.