A serviceman has been threatened with a knife near an RAF base in Norfolk.

Police said he was approached by two men, near the married quarters at RAF Marham in the Burnthouse Drove and Ladywood Road area, on Wednesday. They threatened him with a knife before making off in a dark coloured car, police said.

The Metropolitan Police said anti-terror officers were aware of the incident but said “the investigation remains with the Norfolk Constabulary”.

The Ministry of Defence said it was also aware of the police operation but would not comment further. The victim, who was not in uniform at the time, was unharmed.

Norfolk Police temporarily closed roads around the airbase following the incident and officers have carried out reassurance patrols in the area. The base is home to almost 10,000 people, including members of the RAF, Navy and Army, as well as the civil service and other staff.

A spokeswoman for the base said a families day, scheduled to take place later, would go ahead as planned. The event – which is not open to the public – allows families and friends of service personnel to see the base and watch aircraft displays.