A fire that investigators attributed to arson was extinguished last night outside a Falls Church clinic where abortions are performed. Earlier, Washington area abortion providers said yesterday's shotgun slayings outside a Florida abortion clinic had reignited their fears of violence.

The small fire at the rear of the Commonwealth Women's Clinic, in the 900 block of W. Broad Street, caused no injury, Falls Church police said. It was spotted about 10:30 p.m. by a police officer, who used a fire extinguisher to douse the flames, police spokeswoman Barbara Gordon said. Police said there was no indication of a connection to yesterday's slayings in Florida, and it was not known who had set the fire.

The clinic has been the target of antiabortion demonstrations.

Shortly after the clinic fire, police in the District and in Fairfax County were directed to pay close attention to area medical clinics overnight. "We just want to watch to make sure it doesn't move up from Florida," a District police spokeswoman said.

Earlier yesterday, Washington area abortion providers, reacting to the killing of a doctor and a volunteer escort in Pensacola, Fla., said stepped-up safety precautions might include the hiring of additional security guards.

At the same time, the abortion providers said local and federal law enforcement officials need to be more aggressive in pursuing minor violations, such as trespassing and vandalism, by abortion foes.

About a half-hour before yesterday's fatal shooting, the alleged gunman was seen putting crosses in front of the clinic and was warned by an officer, but the officer left without arresting the man.

"We're going to be as cautious as possible," said Rosann Wisman, president of Planned Parenthood of Metropolitan Washington, which runs seven family planning clinics. "We expect to have increased police protection for at least a period of time."

Local antiabortion activists condemned the shootings and urged abortion rights supporters not to lump everyone in the movement with Paul Hill, the man charged yesterday with killing the Florida doctor and volunteer and wounding another volunteer.

"It's a horrible, tragic, heinous, serious crime," said Judie Brown, president of the American Life League in Stafford. "Each and every individual in this country, regardless of their position on abortion, should have equal opportunity to love, know and serve God, and two people were denied that opportunity this morning."

But Kip Gannett, organizer of Maryland-based Project Rescue, said the killings are a result of federal legislation enacted in May that made it a federal crime to block access to abortion clinics.

"A lot of us who would only engage in nonviolent activities had a mediating effect on the pro-life movement," he said. "When we were taken out of the picture {by the new law}, other elements came to the fore. We're going to see more of this {violence}, and it shouldn't have to happen."

In the last 16 months, three doctors who perform abortions have been shot in the United States. However, abortion providers and abortion rights activists said the Washington area has been largely free of antiabortion violence since a rash of clinic bombings in the mid-1980s.

"We've seen no indication of someone here that seems likely to pull out a gun and shoot someone," said Adam Guasch-Melendez, a steering committee organizer with the Washington Area Clinic Defense Task Force, which provides volunteers to eight abortion clinics to shield patients from antiabortion protesters.

Still, area clinic directors said they question whether current security is sufficient to protect their staff and volunteers.

"We are extremely frightened," said one Maryland doctor who performs abortions. He asked not to be identified. "But I will continue {to provide abortions}. What else can I do?"

One Washington area clinic, which asked not to be identified, has hired an off-duty police officer to provide security on Saturday mornings. "It wasn't enough to hire security," said a spokeswoman for the clinic. "An officer can make an arrest on the spot."

But other clinics have resisted taking that step.

"It's a chilling thing to have to think about hiring armed security," said Larry Selden, Planned Parenthood senior vice president. "To have escorts with bulletproof vests, that's a terrible thing. I hope it doesn't come to that. You're giving a terrible message that this isn't a safe place to come."

The volunteer task force plans to put extra volunteers at clinics this morning and to meet with the D.C. police next month, Guasch-Melendez said. "We'll try to put more {people at each clinic} on the theory that larger groups are better," he said.

Several abortion providers said they want area police to take minor lawbreaking by abortion foes more seriously.

Police treat trespassing and blockades by abortion foes "as a nuisance," said Wayne Codding, operations director of two abortion clinics, one in Foggy Bottom and another in Falls Church. "It's more than a nuisance. They should be arrested and prosecuted. If you don't deal with it seriously ... then it escalates, and people get hurt."

Abortion foes, however, urged abortion rights supporters not to use the deaths to push for more restrictions on abortion opponents. "Paul Hill represents a minority fringe element," said Patrick Mahoney, national spokesman for Operation Rescue. "He in no way represents the tens of thousands of people who peacefully intervene at abortion clinics." Roger Stenson, executive director of Maryland Right to Life Inc., said the media may be partly to blame for yesterday's deaths because Hill received widespread media attention last year when he praised Michael Griffin for fatally shooting another Pensacola abortion provider.

"Does this kind of spotlighting exaggerate his sense of self-importance?" Stenson asked. "I wish this guy had never been printed on the back page in any newspaper anywhere."

Staff Writer Scott Bowles contributed to this report.