Dozens of graves were damaged over Memorial Day weekend at a south suburban cemetery, including several belonging to war veterans, officials said.

As many as 79 graves were pushed over at the Lockport Cemetery, at 528 Madison St., over the long holiday weekend, Chief Terry Lemming said.

Sometime between Friday night and Saturday morning, someone or a group of people, pushed over numerous grave memorials and headstones, damaging many.

Officials called several of the damaged headstones “irreplaceable,” noting that some had been in place for more than 100 years.

Lemming called the acts “despicable,” saying “Memorial Day is a time to remember those war veterans that paid the ultimate price for the freedom of all U.S. citizens.”

He noted some of the veterans buried in the cemetery fought in the Civil War.

“Instead of honoring theses brave veterans, criminals damaged them, which is an insult to the families of the interred and all veterans,” Lemming said in a statement.

A $5,000 reward is being offered for information leading to an arrest. Anyone with information on the incident is being asked to call (800) 323-6734 (815)-838-2132.