(CNN) — Fire officials responded Wednesday to a reported blast and fire at a three-story apartment building in Minneapolis, Minnesota.
Thirteen people have been taken to area hospitals, said Robert Ball, a spokesman for Hennepin County Emergency Medical Services.
Some are in critical condition, he said.
Most of the injuries are from burns and “trauma of people that came out through the windows,” Ball said. Officials don’t know whether people jumped out, fell or were pushed out by the explosion.
Freezing weather in the city presents challenges for firefighters, since water used to try to put out the fire can quickly turn to ice, he said.
Officials were looking into whether anyone may still be inside the building.
CNN affiliate KARE reported that as many as a dozen people were injured.