Vandals targeted Prairie Park Nature Center over the weekend, spray-painting educational trail signs with racist and homophobic graffiti, the latest in a wave of damaging incidents at the park.

“Very rude and crude things,” Roger Steinbrock, marketing supervisor for the city’s Parks and Recreation Department, said of the graffiti. “There’s a giant phallic symbol, some epithets. Somebody misspelled ‘jihad.'”

It was the fourth incident of vandalism at the center, 2730 Harper St., since March.

The skate park at Lawrence’s Centennial Park, Sixth Street and Rockledge Road, has been vandalized three times  the electrical lighting system was damaged and walls were spray-painted  most recently on Labor Day weekend.

Officials are fed up. On Monday, they offered a Crime Stoppers reward for the conviction and capture of the vandals at both locations. And they said they wouldn’t replace the lighting system at the skate park until the culprits there were caught.

“Then we can put them back in without fear of someone getting hurt,” said Tom Wilkerson, assistant director of Parks and Recreation. “Those are dangerous problems because they’re dealing with electricity there.”

Wilkerson said the cost of replacing the light system would be more than $1,000. He didn’t have an estimate for fixing the signs at the nature center.

“If we have to replace those signs, it’ll be thousands of dollars probably,” he said.

More than 40 people called parks officials over the weekend after seeing the nature center damage, Wilkerson said.

Devotees of the trail are frustrated by the repeated damage there, he said. In March, signs were spray-painted and broken. In May, signs were unbolted and thrown in bushes along the trail. In August, graffiti was sprayed on signs along the trail. The earlier graffiti did not include the same kinds of racist language found over the weekend, Wilkerson said.

“There’s been a considerable amount of concern registered by the general public,” he said. “And understandably so.”

Officials are asking witnesses to call the Lawrence Police Department at 832-7501 or Crime stoppers at 843-TIPS. Wilkerson would not specify the exact amount of the reward.

“We’re going to make every attempt to stop them,” Wilkerson said of the vandals. “We just need to protect these facilities for public use.”