Police believe more than two people were involved in the attempted abduction of a serviceman near an RAF airbase.

The married serviceman, who is in his late 20s, was out running near RAF Marham, in Norfolk, on Wednesday when he was grabbed by a man, who tried to drag him towards a nearby car.

Police have today said it was likely that more than just two men were involved in the attack.

Detective Superintendent Paul Durham said: 'While the victim only witnessed two attackers, there may have been more than two people in the vehicle and given the nature of the attack, it is likely they were part of a larger team.

Police outside RAF Marham in Norfolk, after a serviceman was threatened with a knife near to the base

'This is important because I do not want to deter any potential witnesses from coming forward; it is the vehicle we are interested in, regardless of the number of people seen inside.'

It comes after police appealed for pedestrians and motorists to help track down two 'Middle Eastern' men after the attempted knifepoint abduction.

The serviceman knocked the first attacker to the floor and an accomplice, carrying a knife, helped him up before both men fled.

The serviceman was said to have been left 'very, very shaken by his ordeal'.

Police are urging anyone walking or driving along Squires Hill, near to Costcutters in Marham, around the time of the incident on Wednesday to come forward.

Norfolk Police Detective Superintendent Paul Durham said anyone in the area could have vital information.

He added: 'Early CCTV inquiries suggest the road, Squires Hill, was fairly busy throughout the afternoon with pedestrians and cars.

'It is these people we are very keen to speak with - they may regularly use the shop and may have seen something out of the ordinary.

'The vehicle used by the suspects, a dark-coloured people carrier, remains a key line of inquiry and clearly anyone who saw a vehicle similar to this in that area during the time frame should contact us.

'I would stress to people that no matter how insignificant the information may seem to them, it is crucial we have this to piece together a full picture of the circumstances leading up to the incident.'

He said that there may have been an element of 'pre-planning' and terrorism cannot be ruled out as a motive.

He added: 'I can confirm we are treating this as an attempted abduction and detailed inquiries are being carried out at the scene to establish the full circumstances.

'The motivation for the attack remains unclear at this time, and whilst we are currently unable to discount terrorism, there are a number of other possible hypotheses.'

Police are keen to trace the two men, a dark-coloured people carrier and also the 'military-style' knife, with a two-and-a-half to three-inch blade.

Norfolk Police released descriptions of two suspects of Middle Eastern appearance as military personnel were reportedly sent a memo warning them about the incident.

The first suspect is described as between 20 and 30 years old, about 6ft tall, of athletic, stocky build, with dark hair which was long on top. He had a well-groomed beard, was of Middle Eastern origin in appearance, with a dark skin tone and he wore dark casual clothing.

The second suspect is described as being between 20 and 30 but younger than the first suspect and of a slimmer build. He was approximately 5ft 10in tall, clean-shaven, with short dark hair. He was also of Middle Eastern origin in appearance and wore a white T-shirt and dark shorts.

Military bases were increasingly vigilant after the incident although the threat to the public remains unchanged, police added.

Detectives have set up a dedicated hotline appealing for information - particularly from witnesses who saw a dark-coloured people carrier in the King's Lynn area on Wednesday afternoon.