Police carrying out a counterterrorism investigation Thursday swooped in on a man they said was carrying knives in a bag near Britain’s Parliament and arrested him on suspicion of planning terrorist acts.
London’s Metropolitan Police said the 27-year-old man was stopped and detained “as part of an ongoing operation” by the department’s counterterrorism unit.
The department said knives were recovered during the operation.
It said the man was being held at a London police station on suspicion of possession of an offensive weapon and on suspicion of the commission, preparation and instigation of acts of terrorism.
Police said that as a result of the arrest, there is “no immediate known threat” to the public.
Witnesses reported seeing armed police blocking off Whitehall, a street lined with government buildings, and a man on the ground surrounded by police.
A black-clad man could later be seen standing on the sidewalk, surrounded by police, before being put into a police vehicle.
A photo showed a forensic officer looking at a black bag and what appeared to be two knives on the ground.
Security has been increased around Parliament after an attacker drove an SUV into pedestrians on nearby Westminster Bridge on March 22, killing four, before stabbing a police officer to death inside the gates of Parliament. The attacker, Khalid Masood, was shot dead by police.
Police believe Masood, 52, a British-born Muslim convert with convictions for violence, acted alone.
Thursday was Parliament’s last sitting day before Britain’s June 8 election.
Police say there has been a surge in knife crimes in London in the past year.
Britain also faces a threat from international terrorism classified as “severe,” meaning an attack is highly likely.
The Associated Press contributed to this article.