Business owners scrubbed their walls and scratched their heads Monday after antiwar graffiti was spray-painted along the city’s main drag.

The vandalism also disturbed at least one peacenik.

“I’m opposed to the war, but there are ways to protest the war that don’t involve damaging other people’s personal property,” said Marq Conner, 31, who owns the building that houses The Topiary Tree, 716 Mass. “This is going to cost me $200 to $500 to fix, and I don’t think it was worth it.”

Black peace signs and messages such as “Peace Now” appeared Monday on at least 10 buildings on Massachusetts Street between Sixth and 10th streets.

Conner said whoever left the graffiti should find a more productive means of protest — or at least choose better targets.

“If you want to protest a government action, protest the government,” Conner said. “Go spray-paint the White House if you can get away with it.”

One of the buildings vandalized was Jefferson’s Restaurant, 743 Mass., which has a peace sign in its logo. General manager Jason Franklin, 25, said he didn’t understand why someone targeted the business, given that neither he nor the owner has taken a public stand on the war.

“If I had come out and said, ‘I’m the general manager at Jefferson’s, and I support the war 100 percent,’ I would look for something like that to happen to me,” he said.

Allan Hanson, coordinator of the Lawrence Coalition for Peace and Justice, said he didn’t condone the vandalism, but he stopped short of condemning it.

Bobby Goins, office manager for a building at Seventh and Massachusetts streets, washes down the sidewalk in front of a building hit with antiwar graffitti. Several businesses downtown discovered similar vandalism Monday.

“The peace movement in this town is fairly broad, and it’s got a whole lot of positions along the spectrum, and I do not want to criticize other members of the movement because we all share the same goal,” he said.

Hanson said many people who have antiwar signs in their yards have seen them uprooted and torn in recent weeks.

“I think that is equally unacceptable,” he said.

At least one pedestrian on Massachusetts Street said he supported the graffiti despite inconvenience to businesses.

“It’s going to cost them a little bit of money, but hey, it’s war,” said Daniel Edwards, 19, who was hanging out at the corner of Ninth and Massachusetts streets. “You’ve got to do extreme measures sometimes.”

Other businesses vandalized include Starbucks Coffee, 647 Mass., Carlson Wagonlit Travel, 800 Mass., and Signs of Life, 722 Mass.