By DEE-ANN DURBIN

Associated Press Writer

Three armed soldiers from the Michigan National Guard stood at the entrance to BioPort Corp. on Tuesday, reflecting a federal order for tightened security at the nation's only producer of the anthrax vaccine.

``It makes me more nervous, seeing all the security around. But I think it's necessary,'' said Roseann Marlatt, 43, who works for the state Department of Community Health across the street.

The U.S. Department of Defense requested the change and is paying for the additional security. The department assessed BioPort's security measures after the Sept. 11 terrorist attacks in New York and Washington, D.C.

BioPort produces a vaccine to fight anthrax, a bacteria that could be made into a biological weapon. The U.S. military is BioPort's only customer.

BioPort keeps some live anthrax bacteria on its campus. But the amount is too small to be of use to terrorists, company officials have said. They say there is no specific terrorist threat against their facility, which employs more than 200 workers.

``However, in light of current national events, appropriate and prudent security measures are being taken,'' the company said in a statement.

BioPort spokeswoman Kim Brennan Root said the Department of Defense is beefing up security at other facilities around the country.

A spokesman at the Pentagon didn't respond to telephone and electronic messages seeking comment.

BioPort is one of several facilities in Michigan with a National Guard presence right now.

Maj. James McCrone, a spokesman for the National Guard, said 50 troopers remain at Ambassador Bridge and Detroit-Windsor Tunnel in Detroit and the Blue Water Bridge in Port Huron.

On Friday, about 160 National Guard members will go on duty at 16 airports across the state. Those soldiers, also armed, will be stationed at security checkpoints.

Around 200 troops were receiving airport security training Tuesday from the Federal Aviation Administration in Battle Creek.

Other potential targets haven't requested National Guard protection, McCrone said.

A spokeswoman for Detroit Edison Co., which operates the Fermi and Fermi 2 nuclear plants in Monroe County, said the plants have heightened security and likely won't need additional protection.

McCrone said BioPort is the only private facility with National Guard security in Michigan.

He wouldn't say how many soldiers are at the complex or how long they'll be there. The soldiers on duty would not speak to the media on Tuesday.

The military's supply of anthrax vaccine has dwindled in the past year as BioPort, which bought the lab from the state in 1998, has wrestled with production problems.

Last fall, the U.S. Food and Drug Administration found 18 flaws in the Lansing operation, more than half of which were connected to filling and packaging. BioPort plans to submit new documents to the FDA on Oct. 15 and hopes to begin supplying the military again if they are approved.

The production problems have delayed the plan to vaccinate all 2.4 million active and reserve troops.

The anthrax bacteria at BioPort isn't in a weaponized form, which company officials say lessens its value to terrorists.

Weaponized anthrax is in a gas form, Root said.

Still, state employee Nikki Demoia said it makes her ill at ease to see the National Guard troops outside.

``If they didn't give it so much attention, it would be fine,'' said Demoia, 29, who works at the Department of Community Health across the street. ``But now it's like, `OK, we know what's in there.'''