QUINCY, Mass. -- For the third time in as many months, paintball vandals have targeted a Quincy cemetery.

NewsCenter 5's David Boeri reported that more than 30 gravestones, including veterans' markers, have been splattered with paint at the Mount Wollaston Cemetery.

Officials said that last Tuesday, paintball players used cemetery stones as shields and may have damaged them permanently. Workers have been trying several chemicals to clean the stones without causing more damage.

"This is the day that all of us cemeteries need to look beautiful or we get in trouble. That is not a bad thing because we all have pride in the work that we do," said Richard McNeice, Mount Wollaston Cemetery foreman.

Thirty-three gravestones in one section bear the stains of paintballs fired into their faces and backsides. Unlike previous paintball assaults, the paint used in last week's paintballs is not water-soluble.

"The oil-part of the paintball is a problem. It is drawn into the stone," McNeice said.

The cemetery has stones made from 20 different types of granite. Some of the stones memorialize veterans.

"It's heartbreaking. I mean, they can't even let them rest in peace," said cemetery visitor Betty Cugini.

McNeice said he thinks the paintballers were using the stones as shields.

"Probably all hand-carved work. I don’t believe there is anybody around that does that work anymore," McNeice said of the stones.

So far, McNeice has not been able to remove the paint residue from the stones.

"We've tried Oxyclean. We tried to use straight bleach," he said.

Although this is the third time paintballers have used the cemetery, this is the first time officials have asked for the public's help in finding the vandals.