Multiple people have been killed after a tornado tore through the town of Greenfield in Iowa, US.

The tornado left a wide swathe of obliterated homes, crumpled cars and splintered trees, while outside the small town, massive wind turbines were buckled and twisted to the ground.

After devastating the town of 2,000 residents on Tuesday, the storms moved eastward to pummel parts of Illinois and Wisconsin, knocking out power to more than 130,000 customers in the two states.

Greenfield’s hospital was among the buildings that were damaged in the town, which meant that at least a dozen people who were hurt had to be taken to facilities elsewhere, according to Iowa State Patrol Sgt Alex Dinkla.

“Sadly we can confirm that there have been fatalities,” Mr Dinkla said at a news conference Tuesday night, without specifying how many. “We’re still counting at this time.”

He said he thought they had accounted for all of the town’s residents but that searches would continue if anyone was reported missing.

The tornado destroyed much of Greenfield, which is located about 55 miles southwest of Des Moines, during a day that saw multiple tornadoes, giant hail and heavy rain in several states.

Authorities announced a mandatory curfew for the town and said they would only allow residents to enter Greenfield until Wednesday morning.

They also ordered media representatives to leave the city on Tuesday night.

In the aftermath of the storm, mounds of broken wood from homes, branches, car parts and other debris littered lots where homes once stood.

Some trees still standing were stripped of their limbs and leaves.

Residents helped each other salvage furniture and other belongings that were strewn in every direction.

Rogue Paxton said he sheltered in the basement of his home when the storm moved through. He told WOI-TV he thought the house was lost but said his family had gotten lucky.

“But everyone else is not so much, like my brother Cody, his house just got wiped,” Mr Paxton said.

“Then you see all these people out here helping each other… everything’s going to be fine because we have each other, but it’s just going to be really, really rough. It is a mess.”

Multiple tornadoes were reported throughout the state, and one also apparently took down several wind turbines in southwest Iowa.

Some of the turbines caught fire, sending plumes of smoke into the air.

Wind farms are built to withstand tornadoes, hurricanes and other powerful winds.

Iowa had braced for severe weather after the National Weather Service’s Storm Prediction Centre gave most of the state a high chance of seeing severe thunderstorms with the potential for strong tornadoes.