A snow squall that swept through Minnesota is being blamed for a massive pileup along Interstate 94 that had firefighters working to put out several burning vehicles Thursday morning.

The crash happened shortly before 9:15 a.m. and shut down both directions of the interstate near Monticello, according to an online update by Minnesota State Police Sgt. Jesse Grabow, Twenty-nine vehicles were involved in the incident, including about 15 tractor-trailers, he added.

Footage from interstate traffic cameras showed at least one tractor-trailer on fire, and wreckage was seen of another semi that had been carrying tractor tires. By 1 p.m., the interstate's eastbound lanes had reopened, but the westbound lanes were still closed shortly after 3 p.m.

The pileup did cause a number of injuries, the exact number is unclear, WCCO-TV reports. Monticello and the surrounding area had been under a snow squall warning at the time of the incident, and drivers could have been traveling in white-out conditions, according to KARE-TV.