ISLAND PARK, Idaho — Seven people were killed in a fiery crash between a van and a pickup truck on an eastern Idaho highway near Yellowstone National Park, officials said.

The Mercedes passenger van — which was operating as a tour vehicle — collided with the Dodge Ram pickup around 7:15 p.m. Thursday on U.S. Highway 20 near Henry’s Lake, the Idaho State Police said.

Fourteen people were in the van and one was in the pickup. Six people in the van — all foreign nationals — and the truck driver died in the crash, police said.

Two survivors have been hospitalized at Madison Memorial in stable condition; three others who suffered injuries were treated and released, according to a hospital official. Two patients were also taken to Eastern Idaho Regional Medical Center, the hospital said.

The cause remains under investigation, police said.

Henry’s Lake is about 17 miles from West Yellowstone, Montana, which is a gateway to Yellowstone National Park.

U.S. Highway 20 closed for nearly seven hours after the crash and has since reopened, police said.

The victims’ names will be released by the coroner once their families are notified, police said.

ABC News’ Jeffrey Cook and Alyssa Pone contributed to this report.