A motorcyclist and passenger were killed Saturday night in a single-vehicle crash on Interstate 35E in Lewisville, police said Sunday.

Names of the victims had not been released by the Tarrant County medical examiner’s office Sunday afternoon.

The wreck was reported shortly before 9 p.m. Saturday in the 1600 block of I-35E southbound.

“Witnesses reported that the driver of the motorcycle was driving at a high rate of speed and weaving in and out of traffic,” Lewisville police Lt. Dan Rochelle said in a news release. “The initial investigation is revealing that the driver lost control and crashed into a guardrail.”

The motorcyclist and passenger were dead at the scene. Neither was wearing a helmet, police said.

Police closed the southbound lanes for several hours as authorities investigated.