Police in England are investigating if the killing of conservative lawmaker David Amess was an act of terrorism

• Essex police are investigating if the killing of MP Sir David Amess at a constituent event was an act of terrorism.
• Amess was fatally stabbed Friday while meeting with constituents at a church.

Essex police are investigating whether the fatal stabbing of Conservative lawmaker David Amess on Friday was an act of terrorism, Chief Constable Ben-Julian Harrington said.

"It will be for investigators to determine whether or not this is a terrorist incident," he said at a press conference. "But as always, they will keep an open mind."

The investigation is in its early stages, Harrington said, and is being led by officers in a counterterrorism unit.

Amess, 69, was fatally stabbed at Belfairs Methodist Church in Leigh-on-Sea, Essex, where the MP was holding a constituency event. The Essex police said the attack took place shortly after 12 p.m.

Police said Amess was treated by emergency services but died at the scene.

"Today is a tragic day for the families and colleagues of Sir David," Harrington said.

Harrington said a 25-year-old man was arrested immediately at the scene on suspicion of murder and remains in custody. Police recovered a knife at the scene.

"We made it clear at the time of the incident that we did not believe there was any immediate further threat to anyone else in the area," Harrington said.