A woman has been shot and six arrested as counter-terror police raided addresses in London and Kent as part of an ongoing investigation into an ‘active plot’.

The raids came hours after a man – said to be inspired by Islamic State – was arrested with a rucksack full of knives near Downing Street. The incidents were unconnected.

The injured woman, in her twenties, was taken to hospital in an air ambulance but has not been arrested due to the seriousness of her condition. She remains under police guard, the Metropolitan Police revealed in a statement.

Four of the people were detained during an operation at 7 pm on Thursday evening at a property on Harlesden Road, North West London.

A 20-year-old man was arrested near the address and a 16-year-old boy and 20-year-old woman were detained inside the property. A 43-year-old woman was later arrested in Kent.

A video (above), posted by Kieran McKenna on YouTube called “Police Shooting in Willesden London”, shows heavily armed officers raiding the house and discharging their weapons towards the upper windows.

Cops on Willesden High Rd last night at the same time as the shooting. Plain clothes and faces covered. Is this legal? pic.twitter.com/Z3zWmI891L — Pukkah Punjabi (@PukkahPunjabi) April 28, 2017

Police said the property and people connected to it had been “under observation by counter-terrorism officers as part of an ongoing intelligence-led operation”.

“An armed entry was necessary due to the nature of the intelligence that we were dealing with, and involved armed officers firing CS into the address,” explained Deputy Assistant Commissioner Neil Basu, a Senior National Co-ordinator for Counter Terrorism Policing.

Speaking on Friday morning, Mr. Basu said it had been “an extraordinary day in London”, but reassured the public, explaining: “Activity continues around the clock to identify and stop these threats and we are making arrests on a near daily basis.”

He added: “With the attack in Westminster on 22 March so fresh in people’s minds, I would like to reassure everyone that across the country officers are working round the clock to identify those people who intend to commit acts of terror.”