Police investigating the death of Sir David Amess are refusing to rule out a terrorist motive.
Essex Police Chief Constable Ben-Julian Harrington said the case is being led by counter-terrorism officers during a press conference outside Southend Police Station.
"The investigation is in its very early stages and is being led by officers from the specialist counter-terrorism command," he said.
“It will be for the investigators to determine whether this was a terror incident. They will keep an open mind.”
Conservative MP Sir David, who represented Southend West in Essex, died after being stabbed in a church in Leigh-on-Sea where he was hosting a constituency surgery on Friday afternoon.
The 69-year-old long-serving public servant remained in the Belfairs Methodist Church following the incident at around 12.05pm receiving treatment.
An air ambulance was at the scene, as were other emergency vehicles, with the area sealed off and placed on lockdown.
Essex Police arrested a 25-year-old man, then later confirmed the victim had died at the scene.
Later they named Mr Amess.
Speaking at the press conference on Friday evening, the chief constable went on to say: "The response of the emergency services to this incident was immediate and our officers arrived on scene within minutes.
"When they arrived they found Sir David Amess MP, who had suffered multiple injuries.
"This was a difficult incident, but our officers and paramedics from the East of England Ambulance Service worked extremely hard to save Sir David.
"Tragically he died at the scene. A 25-year-old man was arrested immediately at the scene on suspicion of murder. He remains in custody.
"A knife was also recovered at the scene."
Flags at parliament have been lowered to half mast following Sir David's death.
Boris Johnson has spoken of the “shock” and “sadness” around Westminster and the country.
Speaking in Downing Street, the PM said the UK had lost a "fine public servant" in Sir David and one of " the kindest, nicest, most gentle people in politics".
He added: "He also had an outstanding record of passing laws to help the most vulnerable."
Former PM Tony Blair said he was "shocked and horrified" by the news.
"David and I came into Parliament together in 1983," he said in a statement.
"Though on opposite political sides I always found him a courteous, decent and thoroughly likeable colleague who was respected across the House.
"This is a terrible and sad day for our democracy."
