Fairfax County Police stormed a McLean office building yesterday after a small group of masked, club-wielding Libyan students seized it, declaring that it housed an organization that promoted terrorism against opponents of their country's leader, Col. Muammar Qaddafi.

About nine hours after the 12 men who identified themselves as "Libyan students" took over the Libyan student aid office, a police SWAT team broke the building's glass front door, but before a violent confrontation developed they negotiated a peaceful surrender of the group.

Police said they will be held without bail and charged with abducting three workers at the office, run by a private corporation funded by the Libyan government. As part of the negotiations, police agreed not to release immediately the students' names and allowed them to wear hoods shielding their faces as they walked to the police wagons.

The students earlier asserted through television newsman Jim Clarke, a negotiator who they demanded come to the scene, that they had seized documents in the building supporting their terrorism claims. Police said last night that files in the building appeared to be damaged and there were "cascades of paper" in one of the building's stairwells.

Clarke, a WJLA-TV reporter who talked with the students for several hours, said the students were protesting Qaddafi's activities and claimed that the office had been used to "encourage, finance and promote terrorism" against Libyans living in the U.S. The students, Clarke said, feared for their lives and wanted police to close the center.

Fairfax police would not comment on the students' claims and referred those questions to the FBI, which also refused to comment.

Washington lawyer Richard Shadyac, who represents the Libyan office, praised the police handling of the incident.

"These are strictly individuals who are out to get publicity for their position, which is anti-Qaddafi," he said. "As far as we're concerned, they're law breakers and should be prosecuted.

Police said the takeover of the three-story building on 6805 Poplar Place in the middle of McLean began about 8 a.m. when the students, wearing stocking masks and wielding sticks and clubs, walked into the office of the People's Committee for Students of Libyan Arab Jemahariya Inc. and briefly took three employes hostage. The students held the three men for five minutes before loosely binding them and shoving them, unharmed, out a door. Two women employes who were also in the building at the time were released immediately.

An anonymous caller to The Washington Post yesterday afternoon said: "We the people of Omar claim full responsibility for the McLean office building seige for the purpose of destroying Libyan student records."

The Libyan office is run by a Virginia corporation created in 1981 to distribute Libyan government money to 2,100 Libyans studying in the United States. The task was formerly handled by the Libyan Embassy until it was closed by the State Department to protest the country's alleged support of international terrorism.

The McLean center had been "threatened in the past," said Tayeb Ayad, a Libyan student who worked there part time. But "we thought we were protected by American law and American security," he said.

The center has an alarm system but it is turned off in the morning when the about 40 employes are arriving for work, according to Shadyac. Shortly after Mohammed Sasi, 52, opened the building, he, Mohammed Ayeb, 48, and Leu Barnett were tied loosely with a white rope. Two women, Judy Holt and Andrea Barnett, were not bound and were not held, according to police.

Police asked the workers in nearby buildings to close their curtains, but they did not evacuate the area because they did not think the students had any weapons other than the sticks. Police established a command center at the office of Fairfax Supervisor Nancy Falck on the first floor of the building next door.

Sharpshooters surrounded the Libyan building and negotiators began talking with the students over the telephone. At about 1 p.m., a second-floor window at the rear of the building opened and a white envelope dropped on a police car. It contained a note informing police that the students wanted to talk to reporter Clarke and signed "Libyan students," according to Capt. Andrew Page.

Police stressed throughout the afternoon that they hoped to avoid force and to settle the situation "peacefully."

The Libyans' plan to lease the building generated some controversy in McLean when it was revealed more than a year ago. Many office workers in the area said yesterday, however, they were unaware that the center was located in the building.