Conservative MP Sir David Amess died on Friday after being stabbed multiple times at a meeting with constituents. Here is what we know so far:

The Southend West MP was fatally injured at Belfairs Methodist Church in Leigh-on-Sea, Essex, at midday on Friday and died at the scene.

Southend councillor John Lamb, a friend of Sir David, said the attacker was waiting at the church to see the MP and “drew a knife and stabbed him” when he was called. Police said Amess was stabbed multiple times.

Essex police said the response of the emergency services was immediate and officers arrived at the scene within minutes.

A 25-year-old man was arrested immediately at the scene on suspicion of murder and remains in custody. The man is believed to be a British national with Somali heritage. Media reports say he waited at the scene before being arrested.

An air ambulance arrived at the nearby Belfairs sports ground 2.13pm as medics worked to save Amess’s life, but police announced just before 3pm that he had died at the scene.

The Metropolitan police declared the incident an act of terrorism, with early investigations revealing “a potential motivation linked to Islamist extremism”. Police said a knife was recovered.

Detectives are not looking for any other suspects, though the Met said officers were carrying out searches at two addresses in the London area as part of their investigation.

The prime minister, Boris Johnson; the home secretary, Priti Patel; the Labour leader, Sir Keir Starmer; and the Speaker, Sir Lindsay Hoyle, have visited the scene and laid flowers in tribute to Sir David.

Hoyle said there would need to be a discussion in the coming days around MPs’ security and any measures that should be taken.

Patel has asked all police forces to review security arrangements for MPs “with immediate effect”, and said measures will be put in place “for the security of MPs so that they can carry on with their duties”.

The National Police Chiefs’ Council said every UK MP would be contacted by Operation Bridger, a nationwide police protective security operation established in 2016, to discuss safety precautions.

Johnson said Amess was “one of the kindest, nicest, most gentle people in politics”, while former prime minister Theresa May said his death was “heartbreaking”, adding: “A tragic day for our democracy.”

Flags were lowered to half-mast outside parliament following Amess’s death.