Ballistics tests have matched a rifle found in the car of two men arrested in connection with the Washington sniper attacks with the weapon used in the killings, the FBI has said.

The weapon seized from the vehicle occupied by Muhammad has been forensically determined to be the murder weapon

FBI Special Agent Mike Bouchard

Police say they now feel "very positive" that the hunt for the gunman who terrorised the US capital and its suburbs is over, following the arrest of two men found sleeping in a car.

Law officials are now treating the men as suspects in the killings and are scheduled to meet on Friday to discuss filing criminal charges related to the 13 sniper shootings in the Washington DC area which left 10 people dead.

John Allen Muhammad, a former soldier described as an "expert marksman", has already been charged with firearms violations.

His 17-year-old stepson John Lee Malvo, a Jamaican citizen, is the other man detained.

As he is a juvenile, details of all federal court proceedings relating to his case are kept private.

'Hole in car'

Charles Moose, police chief in Maryland's Montgomery County where six people were killed each by a single shot, said it appeared the hunt was over.

John Allen Muhammad was an "expert marksman"

"We feel very positive - we have the weapon, it is off the street."

FBI Special Agent Mike Bouchard confirmed: "The results of forensic testing are that the weapon seized from the vehicle occupied by Muhammad has been determined to be the murder weapon."

Ballistics evidence has shown most of the shootings were from the same gun, and other evidence has allowed police to link all the 13 attacks since 2 October.

Federal officials said the firearms offence charge was a way to detain Mr Muhammad while more evidence was sought in the case of the gunman who managed to kill and escape without alerting witnesses.

Media reports have quoted police sources as saying there was a hole carved in the car which would enable somebody to lie in the back and shoot without being seen.

Former soldier

Mr Muhammad is an "expert" rifle marksmen who served in the army for 10 years, according to the US Department of Defense. He was deployed during the Gulf War and left the army with the rank of sergeant.

The men were found sleeping in their car

He is also known to be a convert to Islam.

The arrests came only hours after warrants were issued and a nationwide hunt was launched for the two men.

Early on Thursday, police converged on a car - a blue 1990 Chevrolet Caprice - on Interstate 70 in Frederick County, about 70 kilometres (40 miles) north-west of the US capital and arrested the men without incident.

The swoop was prompted by an emergency call from a motorist who spotted the car which matched a police description.

The men were arrested as other officers were investigating leads in Alabama - where a woman worker at a liquor store was shot dead in September - and in Washington state, where Mr Muhammad once lived.

	:	Trail of terror
Map showing location of recent attacks

FBI agents searched a house in Tacoma, Washington state, 3,200 kilometres (2,000 miles) from the capital, taking away a tree stump which may have been used for target practice.

Mr Muhammad served in the army at the Fort Lewis base near Tacoma and is believed to have lived in the house.

The firearms warrant issued in Washington state - under which Mr Muhammad was arrested - lists conversations Mr Muhammad was said to have had with a former army colleague.

According to the warrant, the soldier told the FBI Mr Muhammad had tried to make a sound suppressor and said to him: "Can you imagine the damage you could do if you could shoot with a silencer?"