An apparent intruder has been shot with a Taser gun and arrested by armed police after being spotted running towards an entrance gate at the Houses of Parliament.

Officers were seen subduing a man who appeared to be in his twenties just inside the carriage gates entrance at Westminster.

The Independent’s political correspondents were among those who witnessed the immediate aftermath of the man’s arrest.

He was seen being held in a police box – where he was heard shouting “coming for you politicians” – before being placed inside a police van and driven away. He has been arrested on suspicion of trespassing.

Around a dozen police officers were involved in restraining the man inside the gates. A clear plastic bag containing a pair of trainers could be seen on the ground nearby.

One witness said: “I heard police shouting – at first I thought they were just shouting at tourists to stay back – but there was a guy stood just inside the gates facing outwards [away from parliament]. He was just stood there with his arms out being approached by lots of police and wasn’t responding to the screams.

“I heard a crack, which I guess was the taser because I saw the taser wires after, and he went down and very quickly they were all on him.”

The witness said he did not see anything in the suspected intruder’s hands.

Suspect held inside Palace of Westminster (The Independent)

The Metropolitan Police confirmed a stun gun had been used.

A spokesperson said: “A man was detained and arrested by carriage gates inside the Palace of Westminster on suspicion of trespassing at a protected site, at around 11.55am on Tuesday 11 December.

“A taser was deployed. Enquiries into the circumstances continue.”