British police were holding a bearded man carrying a backpack near the scene of an incident close to Britain’s finance ministry and Prime Minister Theresa May’s official residence, Reuters witnesses said.

Police said no one had been injured in the incident close to Prime Minister Theresa May’s official Downing Street residence in Westminster but gave no further details. May was not at Downing Street at the time of the incident, a spokesman said.

A BBC Home Affairs correspondent said on Twitter that two knives had been seen on the ground including a large “breadknife” and added a photograph of an officer wearing a blue forensic suit photographing what appeared to be a knife on the sidewalk next to a rucksack.

A spokeswoman for May said that she was not at her Downing Street residence at the time of the incident on Whitehall, a major street near Britain’s parliament where several government ministries are located.

A Reuters photograph showed the man being held was bearded, dressed in black, appeared to have a white bandage wrapped around his right hand and was in handcuffs.

The incident comes just over a month after a British-born extremist ploughed a car into pedestrians on nearby Westminster Bridge killing four people before stabbing to death a police officer in the grounds of parliament.