MALHEUR COUNTY, Oregon -- A head-on collision and fire involving two commercial semi trucks near Harper, Oregon, has killed two truck drivers.

The crash occurred on U.S. 20 west of Harper, at milepost 216. Oregon State Police troopers responded at about 9:10 a.m. Mountain Time.

In a news release sent Saturday evening, OSP says a truck heading east entered the westbound lane for an unknown reason, into the path of an oncoming truck. The two trucks collided and burst into flames.

The drivers of both trucks were confirmed dead at the scene. On Sunday, OSP identified the driver of the first truck as 37-year-old Brian Brunscher of Springfield, Oregon, and the second driver as 55-year-old James Shorten of Portland.

A Jeep Wrangler and Kia Spectra were behind the westbound truck. The Jeep hit the rear trailer of that truck, and the Kia struck the back of the Jeep. Airbags deployed on both the Jeep and the Kia. The drivers of those cars did not report any injuries.

As of 7:30 p.m. Saturday, U.S. 20 remained closed between Juntura and Harper, as the trucks were still burning. About 400 gallons of diesel fuel spilled onto the highway. The road had reopened by Sunday morning.

OSP says speed and weather conditions are believed to be contributing factors in the crash.