The Libyan students arrested for seizing a McLean office building refused yesterday to reveal their names or disclose any other personal information to Fairfax County authorities.

A judge responded by ordering them held in jail without bond.

Separately, Fairfax Prosecutor Robert F. Horan Jr. said that he had not seen any "hard evidence" to back up the students' charges that the building served as a front for terrorist activities against American-based opponents of Libya's leader, Col. Muammar Qaddafi.

"So far the claims are just rhetorical," Horan said.

The students charged through a negotiator during the siege that they had riffled files in the building and found documents to support their charges.

Fairfax police spokesman Phil Lively declined yesterday to comment on the assertion.

"Any such item would be potential evidence and could not be discussed," he said.

Identified only as "John Doe 1" through "John Doe 12," the dozen young men were arraigned before Fairfax County General District Court Judge Conrad Waters on three counts each of abduction. The defendants allegedly held three persons hostage briefly as the Wednesday incident began.

"None of the students will disclose their names, and there was not a shred of identification on any of them" when the police stormed the building and negotiated their surrender Wednesday evening, Horan said.

When the students were taken from the McLean building to the police wagons Wednesday night, they were allowed to wear hoods. During their brief court appearance yesterday morning their faces were not covered.

Waters set a preliminary hearing on the charges for Jan. 6. If the students have not engaged attorneys by Jan. 3, the judge must decide whether to appoint a lawyer for them.

For nine hours Wednesday the men, identifying themselves only as "Libyan students" occupied the McLean offices of the People's Committee for Students of the Libyan Arab Jamahiriya Inc., a group that distributes money from the Libyan government to the 2,100 Libyans studying in the United States.

The center was established in 1981 after the State Department closed the Libyan Mission here because of what it called "Libyan provocation and misconduct, including support for international terrorism."

No one was injured in the takeover, and the men surrendered peacefully after police broke into the first floor of the three-story building on Poplar Place.

A lawyer who represents the center has denied the students' allegations that the office serves as a headquarters for spying on Qaddafi's opponents in this country and has accused the students of seeking publicity.

More than a year ago, 40 Libyan students occupied the Libyan Mission to the United Nations for three hours before surrendering peacefully. The students were charged with criminal trespassing but were told the charges would be dropped if they stayed out of trouble for six months.

Because the group feared reprisals, Manhattan authorities allowed them to cover their faces with paper bags in their court. Their names and addresses were not revealed in open court, but instead were presented privately at the judge's bench.

In February 1980, Qaddafi, the man the students oppose, called for the "liquidation" of antigovernment Libyans living abroad. He renewed that declaration this fall, threatening in October to send "hit squads" overseas.

In 1980, the U.S. expelled six members of Libya's diplomatic community in connection with the threats.

The State Department has declined to comment on the charges relating to the McLean center.

Since Qaddafi's 1980 threat, more than a dozen Libyans have been killed or wounded in assassination attempts in Great Britain, West Germany, Italy, Greece, Lebanon and the United States, according to Amnesty International. In the last case, Eugene A. Tafoya, a former Green Beret, was convicted in Colorado of the October 1980 shooting of Faisal Zagallai, a leading Qaddafi critic.