British counter-terrorism police said on Friday they had disrupted an active terrorist plot after a woman was shot during an armed raid on a house in north London.

Six suspects were arrested on terrorism-related charges, police said.

The injured woman, who is in her 20s, was in serious but stable condition in a hospital.

Metropolitan Police Deputy Assistant Commissioner Neil Basu said armed anti-terrorism officers fired CS gas into the house in the Willesden area of northwest London, which had been under surveillance.

Asked if police had foiled an active plot, Basu replied: “Yes” – but he did not give details of how the woman was shot.

Neighbor Maxine McKenzie said she saw “a lot of frenetic police activity” and a woman being taken out of the house on a stretcher.

“She was sitting upright and had oxygen on – I couldn’t tell if she was conscious or unconscious,” McKenzie said.

In a separate incident only hours earlier, a man was arrested carrying at least three knives in a backpack near Prime Minister Theresa May’s office in Westminster, during another operation by armed counter-terrorism police.

The 27-year-old suspect, who has not been identified, had also been under police surveillance.

Basu stated that it had been “an extraordinary day in London.”

In both the Willesden and Parliament incidents, “due to these arrests that we have made, we have contained the threat that they posed,” he said, and added that six people had been arrested in the Willesden operation, five at the house and another in Kent, in southeast England.

Counter-terrorism police say 13 potential attacks have been foiled in the last four years.