About 50 opponents of legalized abortions picketed a Montgomery County medical clinic early yesterday as seven members of the group staged a sit-in, blocking entrances to examining rooms and damaging some medical equipment at the facility.

Staff members at the Sigma Reproductive Health Center in Wheaton said that just after the center opened around 8:30 a.m., the anti-abortion group entered the small building on Viers Mill Road and immediately blocked the doors to the clinic's laboratory, examining rooms and treatment rooms.

"They came in and started preaching like they always do, saying you're killing babies. How can you kill babies?" said one staff member, who asked not to be identified.

The staff member also said that a man in the group pulled a hammer from under his coat and smashed several glass bottles attached to an aspirator, a medical suction device used for early abortions.

Montgomery County police yesterday said they have charged Leo Bozell, 53, of McLean, with destruction of property at the clinic. He was being held at the county detention center in Rockville.

Police also charged Rebecca Montgomery, 34, of Herndon, Anne Marie Szymowisz, 32, of Hillcrest Heights, Lesek Steven Syski, 23, of Silver Spring, Gay Laurienzo, 18, of Rockville, and Norman Hackland, 40, of Easton with trespassing.

Staff members at Sigma said several patients were at the clinic when the incident occurred, all of them in the waiting room because the facility had opened only minutes earlier.

"It sure upset some of the patients though, so we moved them to a separate room where they wouldn't have to be harrassed," a staff member said.

"We asked them [the demonstrators] to leave, and when they wouldn't we called the police. They finally left when the paddy wagons came," the staff member said.

An administrator at the clinic, who also asked not be named, said that a similar sit-in occurred about two years ago at the six-year-old clinic. In the last few years, anti-abortion groups have resorted increasingly to sit-ins to voice their objections to legalized abortions and to attempt to discourage women from going to clinics such as Sigma, which offer other medical services in addition to abortions.

Jill Laurienzo, the 16-year-old sister of one of the women arrested for trespassing, said yesterday that the anti-abortion group had gone to the clinic "to try to talk to some of the girls, to talk them out of an abortion."

Laurienzo said that five members of her family -- including both parents -- attended the sit-in to show their support of efforts to close down abortion clinics. "We were planning on getting arrested," she said.

However, Sigma's administrator said yesterday that sit-ins and other attempts to harass the clinics will not decrease the number of women who decide to have abortions.

"Abortions are going to be done regardless and they should be done safely and with proper medical procedures," the administrator said. "It's a choice that should be available to any woman on demand. No one is forced into it."