BOSTON -- Natick police said they were searching for whomever stuffed decorative American flags in trash receptacles around the town square and set them on fire.

Authorities said an off-duty officer noticed a trash receptacle on fire in a Natick park near the Massachusetts Bay Transportation Authority station at about 4 p.m. on Thursday.

"I will tell you -- I was very, very upset about this. This area, this park, Moran Park, is considered sacred ground by the veterans here in Natick," veteran John MacGillivray said.

By Friday afternoon, the 12 flags had been replaced.

"I am aware that people have a right to protest, but they don’t have a right to take property that doesn’t belong to them and that's here to honor the veterans. It is a disgrace," MacGillivray said.

The burning flags were in a solar-powered trash compactor.

"It had to be purposefully set. It is probably not that uncommon to have trash on fire, but it is a little more uncommon to find flags," said Natick Police Lt. Brian Grassey.

Natick veterans said it was especially disrespectful to burn the flags days before Memorial Day weekend.

"We decorate this park every Memorial Day. We have never had anything like this happen," said veteran Bob White.

Those responsible for the vandalism face felony charges for destruction of property for destroying the flags and damaging the trash compactors.

"Perhaps they should be cleaning up this park or something along that nature. If it is young kids, they need to be made aware of the consequences of their actions," MacGillivray said.

A veterans group said it would properly dispose of the flags.

Police are asking for help finding the person responsible for burning the flags. They ask anyone with information to call them at 508-647-9500.