A semi rear-ended a bus full of military personnel on westbound I-94 between Albertville and Monticello on Thursday afternoon, causing the bus to roll over and the semi to veer into the ditch, according to the Minnesota State Patrol.

Six injuries have been reported, according to Master Sgt. Eric Amidon, an Air Force spokesman, but the passengers conditions aren’t known yet. The state patrol said their injuries didn’t appear to be life-threatening.

The bus carried 13 members of the 934th Airlift Wing based in the Twin Cities, who were headed to training in Fargo, Amidon said. A board of officers will be investigating the crash.

The group, known as the Global Vikings, is Minnesota’s only Air Force Reserve unit.

The crash caused traffic to back up in both directions and the highway to close near Albertville as emergency crews assisted the injured passengers.

AirCare landed on the interstate to help and least one person was airlifted from the scene, though the person was conscious, according to the state patrol.

Both lanes were cleared and open again by about 3:40 p.m., the State Patrol said.