A major route into the city will remain closed for the foreseeable future with authorities unable to confirm when it will be back in action.

A section of the embankment beneath the bridge in Sweet Briar Road was washed away after a water pipe burst.

Parts of the pavement along the road, which runs over the footpath in Marriot's Way, have also fallen through.

An Anglian Water spokeswoman, which is responsible for the pipe, said there would need to be an investigation before they would know how much material has been lost and how long it will take to repair the damage.

She said: "We are liaising with the county council to get it fixed but at this point we don't know how much material has been lost until we get someone there to assess it.

"We also won't know how long it will take to get it fixed until we've had someone down to investigate."

Sweet Briar Road is currently closed in both directions between the A1074 Dereham Road and Hellesdon Hall Road.

The road closure caused heavy traffic in the area on the morning of February 18.

Norfolk County Council said the road was not safe to reopen and added it was hopeful there was no damage to the Marriott's Way bridge itself.

A spokeswoman said: "The burst water main has washed away a section of the embankment which supports the outer ring road.

"Given the current road condition and the extent of undermining of the ground under the outer ring road, it is not safe to reopen the road to any traffic until repairs are complete.

"A diversion route for traffic will be in place via Dereham Road, Barn Road and the A1067 Aylsham Road, delays are expected.

"Drivers of large vehicles are reminded to not use Marl Pit Lane and Hellesdon Lane as an alternative route due to the clearly signed three-tonne weight restriction on Hellesdon Bridge.

"Initial feedback from highway bridge engineers is that there is no damage to or current issues with the Marriott’s Way bridge, however the team will continue to monitor the situation.

"The Marriott’s Way Norfolk Trail which runs under the bridge remains flooded and covered in debris and is likely to need to remain closed for safety reasons once repairs to the nearby damaged embankment and road are underway due to the heavy equipment that will be working in the area.

"The route will be reopened as soon as possible."