Volunteers at forecourts help drivers terrified of sniper

Volunteers were offering to refuel cars at petrol stations yesterday as anxiety and concern caused by the sniper shootings continued to grip the Washington area.

At the same time police decided to open a post office box for information on the sniper, a move that may be an attempt to encourage the killer to start communicating with them.

Members of the Guardian Angels said they were positioning themselves at fuel stations to prevent motorists having to leave their vehicles. Five of the 10 victims have been shot at garages.

"We decided to act when we started hearing that people were afraid to go to the gas station," said John Ayala, a member of the volunteer group.

Meanwhile, it was reported last night that police were examining an abandoned white box truck that appeared to have been freshly painted and had registration plates that had been altered. The vehicle, which apparently resemblesthe composite image of a truck released by police at the weekend, was discovered yesterday afternoon in Washington.

By last night the sniper had not struck for three days ­ the longest lull since the shooting spree began nearly two weeks ago. But police admitted that people were still anxious and on edge as they awaited another shooting. Since the evening of 2 October, eight people have been shot dead.

Police Chief Charles Moose of Montgomery County, who is heading the multi-agency investigation, said: "We also admit that everyone is edgy.

"Things occurring that may normally be overlooked or that may be routine are certainly getting a higher response from people in their anxiety."

Chief Moose said he had set up the post office box for information on the sniper, but refused to say whether this was aimed at encouraging the sniper to communicate. It is known that detectives are keen to engage in dialogue with the killer.

Investigators hunting the sniper have listed a number of consistencies: he favours suburban fuel stations; fires a single round and, with one exception, strikes in the morning or the evening. But while officers insist they are making progress, they have refused to release investigative details.

"We don't want to release anything that may cause ... anyone to think they're a suspect," said Mike Bouchard, an agent with the federal bureau of Alcohol, Tobacco and Firearms.

Chief Moose also refused to comment on reports that the FBI had asked the Pentagon to search records for recently discharged soldiers who had trained as snipers.