SAN DIEGO – A mother and her child were hurt Tuesday after being knocked off their bicycles by a suspected impaired driver in Imperial Beach, authorities said.

The crash involving a 78-year-old driver in a Chevrolet Silverado happened shortly before 8:15 p.m. at the intersection of 11th Street and Fern Avenue, San Diego County sheriff’s Sgt. Shane Burt said. The bicyclists were traveling westbound on Fern at the time of the incident.

Both the mother and child were taken to an area hospital. The mother sustained major injuries and was considered in stable condition while the child was released from the hospital with minor injuries. Neither was publicly identified.

The pickup truck driver later was arrested on suspicion he was driving under the influence of drugs, Burt said. He was booked into San Diego Central Jail. His name also was not disclosed.

The investigation into the crash is being handled by Imperial Beach Traffic Units and the sheriff’s department’s STAR Team

No further information was made available.