Eleven persons who have been arrested and acquitted of trespassing charges in connection with antiabortion demonstration at the Northern Virginia Women's Medical Center were ordered by a federal judge in Alexandria yesterday to stay away from the clinic at least temporarily.

U.S. District Court Judge Albert V. Bryan Jr. granted a temporary restraining order against the protesters after a lawyer representing the center concluded his argument by saying: "We just want to have a bunch of strangers, foreigners to private property" prohibited from trespassing "and violating others" constitutional rights" to have abortions.

An attorney for the protesters said he would not be able to appear at the hearing yesterday, Bryan said.

But attorneys for Fairfax County Police Chief Richard King and Commonwealth's Attorney Robert F. Horan Jr. argued in favor of the restraining order. Horan and King had been named along with the 11 activists as defendants in the case but Judge Bryan dropped them from the order. "I have serious doubts about fashioning a remedy, temporary or otherwise, against institutional dependents," Bryan said. "It's a delicate area to get into to start telling state officials what to do."

Attorneys for the Fairfax Prosecutors and the county police voiced grievances at yesterday's hearing against the county's judges who on at last two occasions have refused to convict demonstrators of trespass charges at the abortion center, which is at 3918 Prosperity Ave. in Fairfax.

Fairfax General District Court Judge Lewis Griffith last October acquitted six defendants of trespass charges, saying at the time that "they had a good faith belief that their actions were necessary to save lives," according to the complaint filed by the center's attorney, Philip J. Hirschkop.

Last week another judge, Mason Grove, acquitted eight demonstrators of trespass charges and called Virginia's abortion statute unconstitutional.

The day after Grove's decision, anti-abortion demonstrators protested at the clinic. They passed out leaflets claiming the state's abortion law had been changed, Hirschkop said. He said several persons in the clinic were injured as a result of the demonstration and one woman named in the suit suggested the center should be burned down, Hirschkop said.

" . . . It would be hard to open if a fire destroyed the building," the woman was quoted in court papers as saying.

Horan was originally named in the suit because after the acquittals he directed county police not to arrest any more antiabortion demonstrators on trespassing charges, Hirschkop said.

But Assistant Fairfax Commonwealth's Attorney Steven A. Merril said the county prosecutors had no objection to the restraining order against the protestors. He said Horan told police not to arrest demonstrators on the trespassing charges because the judges would only throw them out again.

"We have tried to prosecute these cases," Merril said. "The court has ruled they would not convict on trespassing" charges.

"I'm in total agreement as far as an injunction is concerned against the individuals going into the clinic," Merril said.

Assistant County Attorney David Stitt said the police will continue to respond to calls at the center and make arrests other than on trespassing charges.

"The poilce feel they're in an untenable situation where the prosecutor has said he will not prosecute any more cases," Stitt said. If police arrest the demonstrators they could be sued for violating the demonstrators' civil rights, Stitt said.

Bryan said he granted the order under a federal law concerning private conspiracies to violate civil rights. The order specifically said the protesters could not "go upon or remain upon the lands, buildings or premises" of the abortion clinic or ask others to protest there.

The restraining order is in effect until Feb. 24 when another hearing is scheduled on the issue, Bryan said.