The U.S. Naval Academy has told gay rights activists that they might be arrested if they go ahead with a planned noontime rally tomorrow to protest the military's "don't ask, don't tell" policy.

Organizers of the event, called Equality Ride, were warned by the school in a letter dated Tuesday to stay away.

"Be advised that accessing the Academy grounds for the purpose of protesting or engaging midshipmen, faculty and staff, may subject you to arrest and prosecution," wrote Capt. Helen F. Dunn, the academy's deputy superintendent.

The 4,000-student school along the Severn River in Annapolis is open daily to visitors and tourists. But officials say they do not allow special interest groups to promote their causes within the academy's walls.

"While the Naval Academy supports and defends every citizen's right to freedom of speech, we also have an obligation to ensure our mission and activities are free from disruption," Cmdr. Rod Gibbons, an academy spokesman, said in a statement.

Introduced as a compromise measure in 1993 by President Bill Clinton, "don't ask, don't tell" allows gay men and lesbians to serve in the military only if they keep their sexual orientation private. More than 9,500 service members have been discharged under the statute, according to the Government Accountability Office.

The threat of arrest has forced Equality Ride organizers to reevaluate their plans. A group of about 60 students, most of them from the Washington area, intended to meet at the academy's main gate, at Randall and King George avenues, for an 11:30 a.m. news conference.

From there, group members planned to march onto the grounds, eat lunch and talk to midshipmen about the effects of the "don't ask, don't tell" policy. They hoped to end the day watching one of the many Friday parades the Naval Academy features each autumn.

"We have not yet figured out what the consequences would be if there's an arrest," said Equality Ride director Jacob Reitan, 23, of Lynchburg, Va. "It's very likely we will still go on the campus and submit to arrest, even if it's as serious as a felony, but we have to be pragmatic about it."

The federal crime of trespass on a military reservation is typically considered a petty misdemeanor punishable by up to six months in jail, a fine of up to $5,000 or both, according to federal law.

The event was organized by Soulforce Inc., a Lynchburg-based nonprofit organization aimed at ending discrimination against gay, lesbian, bisexual and transgender people. The Naval Academy is the second of many stops the group plans at schools where homosexuality is banned or discouraged. Last April, the group visited the Rev. Jerry Falwell's Liberty University in Lynchburg.

"Ironically, Jerry Falwell allowed us onto the campus, and we had a fruitful dialogue," Reitan said.