GENEVA (AP) - The International Red Cross said Sunday it was 'improbable' - but not impossible - that a laboratory in Afghanistan that made an anthrax vaccine could be adapted by terrorists to create a deadly strain of the virus.

"I don't want to say it's impossible because you don't know what is impossible," said Kim Gordon-Bates, spokesman for the International Committee of the Red Cross. "We are concerned but we are not unduly worried."

Gordon-Bates said the ICRC had no information about what had happened to the laboratory since the agency's international staff withdrew from Afghanistan on Sept. 16 following the terrorist attacks on the United States.

Confirming a report in the French weekly Journal du Dimanche, Gordon-Bates said the laboratory was set up in 1997 in the Afghan capital, Kabul, to make an anthrax vaccine to treat animals. It was established by the ICRC but owned by the Afghan ministry of agriculture.

He said scientists used a strain called 34F2 Sterne, which is completely harmless for humans.

"It's a strain you find round the world and the vaccines were made quite traditionally. This is a fairly rudimentary laboratory - it only cost dlrs 125,000 to set up and you aren't talking about something that's shining, sterilized, sparkling clean," Gordon-Bates said.

"The only question mark that remains is whether the facility could have been used with other strains and that, I think, is highly improbable."

The French newspaper said Islamic militants had shown interest in the laboratory and it has already been targeted by burglars once.

It said, without citing sources, that the French intelligence service is concerned that networks run by Osama bin Laden might try to take over the laboratory and use it to produce biological weapons.

Gordon-Bates said he had no information at all about the situation at the laboratory but it had continued to operate after international staff withdrew.

"Contacts with the people who stayed behind in Kabul are very, very difficult," he said. "But I must point out that the Afghan staff who were left behind were highly trained and very competent."

He said the ICRC was negotiating with the ruling Taliban to regain access to Afghanistan, and the fate of the laboratory would be one of the first things that staff would want to know when they were allowed to return to Kabul.

Fears that terrorists could use anthrax as a biological weapon have been heightened by cases in the United States. One man died in Florida from the rare inhaled form of the virus, and another seven people have tested positive for exposure.

In New York an employee of NBC television news is being treated for anthrax after receiving a threatening letter, and a second person is showing signs of the virus.