The Marine Corps has transferred 13 enlisted men -- five of whom work on the White House helicopters -- because of suspicions that they smoked marijuana off duty.

"It's strictly suspicion," said Lt. Col. Arthur Brill, a Marine Corps spokesman, "But suspicion in this case is good enough to warrant transfer."

The transfer of the men, in their late teens or early 20s, follows an investigation earlier this week by an internal security unit. Officials said yesterday the investigation was sparked by an informant's report.

The elite Marine Corps squadron, based at Quantico Marine Base in Prince William County, ferries the president, the first family and other VIPS including foreign heads of state, on short flights around the country.

Some of the marines suspected of smoking marijuana "are the ones, responsible basically for keeping the helicopters fit to fly." Brill said. "It's obvious what happens if they're not fit to fly. You bet your life it's a concern to us," Brill said.

The Marine Corps said yesterday that the transfers effective today, concludes the Corps' inquiry into the matter. No charges are expected to be brought against the men, who will be transferred out of the Washington area, to bases in North Carolina and California.

According to a statement released jointly by the White House and the Pentagon last night, "the investigation did not produce any conclusive evidence that any of the 13 used marijuana on or off duty."

The unit's commanding officer, whom Pentagon officials did not identify, confronted the men with the accusation this week. "They did not confirm or deny it," Brill said.

Corps officials said that they did not know how many of the unit's more than 300 mechanics were assigned to work on the eight helicopters in the presidential helicopter fleet. The squadron has 52 officers and 397 enlisted personel.

Corps officials said the incident was "of concern" to the prestigious squadron, founded in 1947, but the spokesman added that "more than 90 percent" of the entire Corps do not break the law.

"We're a reflection of society," said Brill. "There is drug use in the Marine Corps like there is in all other segments of society."