HONOLULU -- Police are seeking vandals who targeted the Honolulu Zoo with what police believe are gang-related graffiti tags.

Zookeepers first spotted the vandalized exhibits Monday afternoon.

"Sometime between 12 and 2 o’clock this afternoon our keepers started radioing in they were noticing that the graffiti had been marked on the glass panels that we have for viewing," said Sid Quintal, city enterprise services director.

The vandals targeted six exhibits and a total of more than 20 glass panels were damaged.

One of the marked exhibits is home to local zoo celebrities, orangutans Rusti and Violet, and another exhibit houses the zoo's Komodo dragon.

Officials believe the vandals used a sharp tool or ring to etch the glass.

"We are asking anyone that has been at the zoo today, if they have been seen any individuals, any groups, noted anything suspicious, groups around the exhibits, to contact HPD, or they can contact us at the zoo and we will certainly refer them to HPD," Quintal said.

Two security guards patrolled the zoo Monday afternoon but did not notice anyone acting suspicious.

Visitors on Monday said the zoo is not a place where they would expect graffiti.

"I think it’s wrong. I don’t know why anyone would go to the zoo and try to vandalize something here," visitor Kuulei Smith said.

It could cost an estimated $15,000 to either repair or replace the displays.

Quintal said the zoo faces a budget crisis and repairs to the exhibits take funding from other zoo improvements.

"It’s just disheartening," Quintal said. "It’s almost like your home being burglarized because you don’t know who did it."

Zoo officials are offering a reward for any information on the case.