Anti-terror police have offered to support the investigation into the attempted abduction by two men of a serviceman outside an RAF base.
Officers from the Metropolitan Police's Counter Terrorism Command are offering support to Norfolk Constabulary which has released e-fits of the two suspects and has been hunting them for more than a week.
The search began last Wednesday when a married serviceman in his late 20s said he was out running near RAF Marham, in Norfolk, when he was grabbed by a man who tried to drag him towards a nearby car.
He told police he knocked the first attacker to the ground and an accomplice, carrying a knife, helped him up before both men fled.
Terrorism has not been confirmed as a motivation for the attack but neither has it been ruled out.
A Scotland Yard spokeswoman said: "Officers from the Met's Counter Terrorism Command are offering support to Norfolk Police but there is no evidence at this time to suggest terrorism as a motive; we cannot discount it but there are equally other plausible lines of inquiry which are being followed, so we continue to retain an open mind.
"The investigation continues to be led by Norfolk Police. The Counter Terrorism Command's role is only to offer support to them at this time."
On the week anniversary of the attack Norfolk Police renewed its search by setting up six road blocks with officers stopping vehicles, asking drivers whether they had been in the area last week and whether they witnessed anything unusual.
Police said the first suspect was aged between 20 and 30, about 6ft, athletic but stocky, with dark hair which was long on top, and a well-groomed beard. He had a dark skin tone and wore casual clothing.
He may have a facial injury sustained during the incident when the victim defended himself, and NHS England has been notified of this.
The second suspect is described as between 20 and 30, but younger than the first suspect, and slimmer.
He was about 5ft 10ins, clean shaven with short dark hair and wore a white T-shirt and dark shorts.