Detectives investigating the attack which led to a Norwich man suffering critical injuries in a car accident last night moved to reassure key witnesses who may be too scared to come forward.

Detectives investigating the attack which led to a Norwich man suffering critical injuries in a car accident last night moved to reassure key witnesses who may be too scared to come forward.

An investigation team has now been formed after Shane Wilson, 18, of Motum Road, Norwich, was hit by a Citroen Saxo while fleeing two knifemen on the city's Dereham Road on Wednesday night.

Mr Wilson, who suffered serious head and leg injuries, remains at the Norfolk and Norwich University Hospital where his condition is still "serious but stable". Members of his family were by his side yesterday.

Officers are pursuing a number of leads and are hoping to be able to speak to the victim this morning. It is possible Mr Wilson knew his attackers.

A large number of witnesses have already come forward including the group of men Mr Wilson was talking to at the time of the attack. Police remain convinced that the two knifemen are local to the Bowthorpe or Larkman areas and that the community could hold the key to their arrests.

Spokesman Kristina Fox urged anyone with information to come forward and said that if necessary they can give evidence anonymously.

Mrs Fox added: "The inquiry is progressing well but we are sure there are still people out there who may have crucial information but have not yet come forward.

"If people are concerned about the repercussions of coming forward they can contact us in the strictest of confidence via Crimestoppers."

The incident happened at about 10pm, 100 yards on the county side of Dereham Road's junction with Norwich Road in Costessey. Both men were carrying knives - one about 12 inches long - and made off towards the Clover Hill areas.

They were in their late teens or early twenties, had dark hair, were about 5ft 7in and were of slim to medium build. Both were wearing dark clothing, possibly tracksuit bottoms.

Members of the NR5 Project, a community-based charity which Mr Wilson attended, spoke of their shock at the incident.

Sonia Bush, from the charity, said: "He is very well liked by everyone in the team. He always wants to do what he can to help and is a nice young man growing up in a deprived area.

"He has got a lot of friends and in this tightly-woven community there will be a lot of support for him at this time."

Contact Norwich CID on 0845 456 4567 or Crimestoppers anonymously on 0800 555111.