The fatal stabbing of Conservative MP Sir David Amess in Essex has been declared as a terrorist incident, police say.

Sir David, who represented Southend West in Essex, was stabbed on Friday afternoon during a surgery at Belfairs Methodist Church in Leigh-on-Sea.

A 25-year-old man was arrested at the scene on suspicion of murder, and he is in custody at an Essex police station.

In a statement, the Metropolitan Police said the early investigation revealed “a potential motivation linked to Islamist extremism”.

Officers are currently carrying out searches at two addresses in the London area, the Met said.

The force believe the man acted alone and are not seeking anyone else in connection with the matter, but inquiries into the circumstances of the incident are continuing.

Sir David was found with multiple injuries and, despite the efforts of police officers and paramedics, the MP died at the scene.