A series of tornadoes have hit the midwestern US state of Minnesota, killing at least three people and injuring dozens.

State officials said 39 tornadoes struck Minnesota on Thursday.

If that figure is confirmed, it would exceed the previous state record of 27 sightings in one day, in 1992.

Mark Roche, an emergency official, estimated that at least nine of the tornadoes churned along a 29-to-32km path in rural southern parts of Minnesota, including Freeborne county.

Roche said the tornadoes damaged 40 to 60 farms, but spared communities.

A visible line of damage was also spotted in North Dakota.

The Red Cross set up a shelter, but officials said no one slept there, opting instead to stay with family, friends or in local hotels.

US meteorologists said the tornadoes developed from the same warm, frontal boundary that started in the southern plains earlier in the week and moved northward through the region.