ANDOVER (AP) — Officials in Andover say they believe several grass fires in the area were intentionally set.

Andover Fire Chief Dan Winkel says about 10 fires were burning in the area Saturday afternoon. He says it appears they were the work of arsonists, and authorities are investigating because of there were so many fires, with different ignition sites, reported in just an hour's time.

The Department of Natural Resources is investigating. If it finds the fires were set by arsonists, a criminal investigation will continue.

Crews from the DNR and the U.S. Fish and Wildlife Service helped fight the fires.

The DNR says there is a moderate wildfire danger in the metro area. There are burning restrictions in Anoka, Chisago, Dakota, Hennepin, Isanti, Pine, Ramsey, Sherburne, Washington and Wright counties.