Two 18-year-olds and a 19-year-old were arrested on Monday morning in east London on suspicion of planning terror attacks, the Metropolitan police said. They are being held at a police station outside London.
The arrests were part of an “ongoing intelligence-led operation”, police said.
Ten people have now been arrested under the Terrorism Act since Thursday evening, when armed police swooped on a terrace house on Harlesden Road, Willesden, shooting and injuring the 21-year-old woman and firing CS gas canisters.
That raid was carried out by elite counter-terrorism specialist firearms officers (CTSFO) and is believed to have been the first time the unit has opened fire during an operation. Dramatic footage filmed by witnesses showed armed officers in black pointing weapons at the upstairs window of the property.
The injured woman was arrested on Sunday immediately after being released from hospital, where she had spent two days recovering under police guard.
Witnesses said the injured woman, who was wearing a long dress and hijab, shouted at paramedics not to touch her body as she was treated at the scene.
Four people, one of whom was a 16-year-old boy, were arrested, including two people who returned to the house in the early hours of Friday morning. A man aged 21 was arrested nearby and a 43-year-old woman was arrested in Kent.
Speaking on Friday, deputy assistant commissioner Neil Basu said the raids were in response to an active plot, adding that police had “contained the threats”.
On Saturday Westminster magistrates court extended the detention of those arrested to dates between 2 and 4 May.
One of those arrested is believed to be Mohamed Amoudi, 21, a British citizen of Yemeni origin who was deported from Turkey in 2015 and questioned on his return to the UK but released without any further action.
The former Queen Mary University student was arrested in Turkey in 2015 on suspicion of planning to cross the border into Syria alongside two 17-year-old schoolboys, the Times reported at the time. The three were arrested again on their return to the UK but released without charge.
Scotland Yard said the Willesden house had been “under observation by counter-terrorism officers as part of an ongoing intelligence-led operation”, adding that the incident was not connected to the suspected attempted terrorist attack in Westminster earlier on Thursday.