Army denies anthrax attack link

Senate buildings have been closed for two months

Anthrax bacteria used in a string of attacks in the United States did not come from the country's military stocks, US authorities have said.

The denial came after the Washington Post quoted scientists investigating anthrax mailed to Capitol Hill as saying that tests had found it identical to a strain developed by US Army scientists at Fort Detrick in Maryland.

The anthrax contained in the letters under investigation absolutely did not come from CIA labs

CIA spokesman

The paper said only five other laboratories in the world had spores with genetic matches to the Ames strain of anthrax in question - and that all of them could trace their supplies to the laboratory at Fort Detrick.

Both the US Army and the Central Intelligence Agency say the bacteria was in a different, powdered form from their stocks, and could not have come from their programmes.

FBI sources have said a possible CIA link is being investigated because of a contractor who used to work in the agency's anthrax project.

Liquid strain

Fort Detrick is home to the US Army Medical Research Institute of Infectious Disease.

Targeted: Senate Majority Leader Tom Daschle

A spokesman, Chuck Dasey, said the research institute's supply had come from the Agriculture Department.

It had then been shared with up to five other labs - three of them in the US, one in Canada and one at Porton Down in the UK.

Mr Dasey was dismissive of the scientists' reported discovery. "I'm not sure it tells us anything about who the perpetrator is," he told the Associated Press.

"You can't say it all came from USAMRIID."

Scientists at Fort Detrick use the liquid strain of anthrax in research, Mr Dasey said.

"The point is we don't have the technology to make that fine dry powder which was in the letters."

The CIA was even more sure.

A spokesman, Mark Mansfield, said the anthrax sent in letters to Senators Tom Daschle and Patrick Leahy "absolutely did not come from CIA labs".

Five dead

The tainted letters were sent to the senators on 9 October from an address in Trenton, New Jersey, and sparked widespread fear following the suicide airliner attacks the previous month.

Anthrax letters were also sent to three media organisations.

Five people have died and 13 have been infected with the disease.

The investigation has recently been downplaying early suggestions that the anthrax bacteria came from another country's biological weapons programme.

Instead the FBI has in recent weeks been turning its attention towards a domestic source.