SALEM, Ore.—A shooting involving an Oregon State Police trooper on Monday left one person dead and closed all northbound lanes of Interstate 5.

Few details on the shooting in Salem, Oregon, were released. The Oregon Department of Transportation said northbound I-5 was closed for police activity, along with one southbound lane. The Oregon State Police issued a statement saying “a suspect is deceased” and that a trooper was involved.

The partial closure of the main highway connecting California, Oregon, and Washington state caused traffic jams. Traffic will be impacted in the area for several hours, the Oregon State Police said.

The Salem Police Department will take the lead in investigating the shooting, the state police said. The slain person was not identified.