DOZENS of armed police swooped on an address in Darlington last night and mounted a four-hour stand-off - only to discover the house was empty.

The alarm was raised after several calls from concerned neighbours who heard gunshots and reported seeing a group of a dozen men fleeing from the scene.

Within minutes, police converged on Salters Avenue, Haughton, and cordoned off the scene.

The "siege" caused mayhem in the area, with residents ordered to remain outside the police tapes, and cars were restricted access.

More than 30 officers, half of them armed, took part in the operation, between 4.30pm and 8.30pm.

Two armed response vehicles arrived and officers mounted a containment operation. Further officers from the armed specialist unit were also called in as a police helicopter circulated the area.

Speculation among residents was rife, with many believing that somebody had been shot.

A neighbour said: "The police did not tell us anything - they just stopped us from going back to our homes. We live here, we should have been told what was going on."

Police officers were unable to establish if the semi-detached house was occupied so they sent in a search dog with a closed-circuit camera attached to its head.

When the dog's search drew a blank, armed police entered and found signs of a hurried exit. A number of windows were found to have been broken.

The man in charge of the operation, Chief Superintendent Michael Banks, said that, while it appeared that no one had been injured and it was unclear if or why shots had been fired, a criminal investigation had been launched.

People living in the vicinity are to be interviewed and anyone who witnessed the incident, or has any information, is asked to contact Darlington Police urgently on (01325) 467681.