SILVER SPRING, Maryland, October 22 (IslamOnline & News Agencies) - Police launched a new major hunt across the Washington region Tuesday, October 22, after a bus driver was shot and killed, sparking fears that a serial sniper had claimed a 10th fatal victim.

Police did not immediately link the killing of Conrad Johnson to the sniper but said the shooting was being investigated as if it were another in a string of sniper attacks, which have left nine dead and three wounded, reported Agence France-Presse (AFP).

Montgomery County Police Chief Charles Moose, who is coordinating the hunt, said Johnson, a 35-year-old father of two, was killed as he stood on the steps of his bus before dawn and that his killer had escaped.

“At this point we have no vehicle lookout to share. We have no person lookout to share,” Moose told a somber press conference.

A single shot felled the man in a way chillingly similar to the other nine deaths and three woundings blamed on the sniper since October 2.

Helicopters buzzed overhead as police cast a new dragnet around the scene of the killing in the Aspen Hill district of Montgomery County.

Police cordoned off the bus stop along tree-lined Connecticut Avenue, a main route linking Washington to the sniper-fearing northern suburbs.

Commuters caught in traffic jams of up to 16 kilometers (10 miles) took two or three hours to get into Washington as police carried out car-by-car checks on major roads.

The sniper’s spree opened with five murders over 16 hours in Montgomery county, near the latest killing.

All the targets were hit as they went about daily activities.

One man was riding a lawn mower, four were killed in gas stations and others in shopping mall car parks.

“We remain concerned about the safety of all the people in our region,” Moose said.

“We realize that the person, or the people, involved in this have shown a clear willingness and ability to kill people of all ages, all races, all genders, all professions.”

The last confirmed victim was a 37-year-old man shot Saturday October 19, outside a restaurant in Ashland, Virginia - some 145 kilometers (90 miles) south of Washington.

He is in critical condition in hospital.

At the scene of that investigation, police found a letter that included a telephone number and apparently sought to communicate with police.

The letter was hostile, threatening further violence and demanding money, according to The Baltimore Sun newspaper, citing police sources.

Moose sought to establish some kind of communication with the sniper, or someone close to the killer at earlier press conferences this week.

“The message that needs to be delivered is that we are going to respond to a message that we have received.

“We are preparing a response at this time,” he told reporters Monday, October 21.

A few hours later, Moose said investigators wanted a new chance to talk to someone who had made contact on a special line.

The Sun reported that someone called the number and left what was apparently a garbled recorded message, according to police sources.

“The person who called could not hear everything that you said. The audio was unclear and we want to get it right.

“Call us back so that we can clearly understand,” the police chief told reporters, again declining to explain the apparent contacts but urging the media to repeat his appeal as much as possible.

The only previous message from the sniper was left at the scene of a previous shooting when he reportedly wrote on a Tarot card: “Dear Policeman, I am God.”

Some schools in Virginia were closed Monday and remain closed Tuesday.