ELK CITY, Okla. (AP) – A minivan carrying 12 people skidded off an icy highway early Sunday and slammed into an oncoming tractor-trailer, killing seven, the Oklahoma Highway Patrol said.

The eastbound van slid through the center median and struck a westbound tractor-trailer on Interstate 40 around 3:50 a.m., trooper Kera Philippi said.

Five of the van’s occupants were taken to a hospital, Philippi said.

Their injuries did not appear to be life-threatening, a hospital spokesman said.

The identities of the woman and six men who were killed were not immediately released. Philippi said all the van’s occupants were adult residents of Mexico, and interpreters were being used to locate next of kin.

All seven victims were thrown or partially thrown from the minivan and apparently were not wearing seat belts, trooper Chris Laufer said. They were pronounced dead at the scene, he said.

At the time of the crash, about 110 miles west of Oklahoma City, freezing rain was falling and visibility was limited, according to the National Weather Service. A powerful winter storm had coated roads and highways with ice and sleet.