The San Bernardino County Sheriff’s Department has issued a warning to parents after hidden razor blades and other dangerous items were found on a playground in Oro Grande, authorities said Wednesday.

The frightening discovery was made on Tuesday at Oro Grande Park (map) by a park maintenance employee. The objects, which included double-edged razor blades, bent forks and other sharp items, had been placed into sand and equipment on the playground, according to a news release from the Sheriff’s Department.

“Many of the blades were wedged into the playground equipment with intent to conceal the dangerous items so they would injure the children,” the release stated.

Authorities were searching for leads in locating the person or persons who put the dangerous objects on the playground.

“We need to protect our children and we need anyone who has information regarding this serious crime to come forward,” Sgt. Jim Evans said in the release. “We are thankful to park employees for doing a thorough inspection of their facilities and locating these dangerous items before a child was injured.”

Although the incident was described as “isolated,” parents were being encouraged to examine all playground equipment and surrounding areas as a safety precaution.

Anyone with information about the investigation was asked to call Deputy Brandon Kirkendall with the Sheriff’s Department at 760-552-6800.

Those wishing to remain anonymous were encouraged to call the We-Tip Hotline at 1-800-782-7463, or leave information through the website www.wetip.com.