Updated

Authorities say two inmates who escaped after stealing a prison transport van in northwestern Oklahoma may now be armed.

Major County Sheriff Steve Randolph says inmates Andrew Foy and Darren Walp overpowered two transport officers about 3:30 a.m. Tuesday and took the van on U.S. 412 north of Fairview. The small city is about 80 miles (129 kilometers) northwest of Oklahoma City.

Authorities say the van was found about 13 miles (21 kilometers) away in Ringwood, and an empty gun holster was found inside. An oilfield company truck was later reported stolen in the area.

Authorities say the inmates were being taken by a transport company to a correctional facility in Kansas.

It was not immediately clear where the inmates were from or what crimes they were convicted of committing.