NORFOLK, Va. (AP) _ Twenty-three sailors aboard the aircraft carrier USS Theodore Roosevelt have been demoted, fined and given extra duty for refusing to take mandatory anthrax vaccinations, according to the Navy.

The refusals are the latest headache for the Defense Department, which has encountered resistance as it seeks to inoculate all 2.4 million active duty and reserve military members by 2005.

The New York Times reported today that the Marines Corps has been particularly hard-hit, with more than two dozen Marines in Okinawa refusing the vaccine.

The vaccinations were ordered a year ago by Defense Secretary William Cohen for all military units sent to the Persian Gulf.

Initially, 38 Roosevelt sailors balked at the vaccinations, which began two weeks ago as the carrier prepared for a six-month deployment starting March 26. Some sailors later changed their minds, Navy officials said.

In the past year, 50 to 100 service members are known to have resisted inoculation. In February, 11 California Air Force Reserve pilots chose to quit rather than take the anthrax vaccine.

One of them, Airman 1st Class Jeffrey Bettendorf, 25, chose an ``other than honorable'' discharge to avoid a special court-martial. He said his research showed the vaccine is untested and unreliable.

The Navy confirmed the Roosevelt situation Wednesday following an inquiry by The Virginian-Pilot, which received an anonymous e-mail message from a sailor who said sailors were concerned about potential side effects.

``I was given nothing to explain what I was taking, so I did my own research and found disturbing reports,'' the sailor said. ``We are scared.''

Cmdr. Garry Rudolph, a Navy doctor who directs the occupational health and preventive medicine program at the Portsmouth Naval Medical Center, said the anthrax vaccine is safe.

Navy officials confirmed last year that a sailor on the destroyer USS John S. McCain developed a temporary paralysis after being vaccinated. Officials said the sailor fully recovered.

The Navy contends it has provided sailors with information about the vaccine, answered their questions and offered counseling to those who initially refused.

The holdouts on the Roosevelt were charged with disobeying an order and punished with a reduction in pay, fines, restriction to the ship and extra duty.

The Navy refused to identify any of those punished but said they may be given administrative discharges once the ship returns.