ROGERS — A series of explosions forced the evacuation of hundreds of residents of an apartment complex in the northwest suburbs of Minneapolis on Sunday.

A problem occurred in a generator located above an underground propane tank at The Preserve at Commerce in Rogers, said Jennifer A. Johnson, a spokeswoman with the Hennepin County Sheriff’s Office.

The explosions happened around 8:45 a.m. No injuries were reported. Johnson said 12 of the complex’s 192 units were damaged, but residents were eventually allowed to return home.

The first explosion occurred in a large propane backup generator pavilion on the northeast corner of the property, according to the sheriff’s office. Police and firefighters arrived to find flames and smoke coming from the generator. Gas continued to leak from the generator, causing several smaller explosions after the initial blast.

The State Fire Marshal’s Office and the Office of Pipeline Safety are investigating the cause of the explosion.

Around 400 to 500 residents were evacuated to a nearby motel and a nearby movie theater, the sheriff’s office said. The Red Cross and Salvation Army assisted with the evacuation. Metro Transit buses were also brought in to keep residents and first responders warm.

The temperature was around 10 below with a wind chill of about 27 below in Minneapolis at 9 a.m., the National Weather Service said.

“Everybody is really shaken,” Rogers Police Chief Jeff Beahen said of the people who were evacuated. “It knocked people off their feet.”

Dillon Czanstaowski and Brian Dongoski, who live on the other side of the complex from where the blast went off, said they felt the explosion before they saw it.

“I thought it was a car that drove into the building. It shook the whole building. It was crazy,” Czanstaowski said.

“Suddenly it was just like, boom, and everything shook. It felt like somebody up on top of us, in the apartment above, dropped something like a fridge or stove, hard,” Dongoski said.

Beahen said that “the luck here is the generator system is outside the complex.”