By Brendan O'Brien
Oct 4 (Reuters) - A tornado at least a mile (1.6 km) wide was reported in Iowa on Friday as a series of twisters swept through the U.S. heartland, causing significant damage, according to the National Weather Service.
The wide tornado was spotted in Woodbury County and again in Plymouth, Iowa, and caused major damage between 6:30 p.m. and 7 p.m. local time, according to preliminary reports by the weather service.
It was unclear whether it was the same tornado, according to Billy Williams, a NWS meteorologist in Sioux Falls, South Dakota.
Damage was also reported in Wayne, Nebraska, Quimby, Iowa, and Union, South Dakota, according to the weather service.
"There has been some significant damage, but we don't have all of the details yet," Williams said.
The National Weather Service is forecasting severe weather throughout the region through Friday night. (Reporting By Brendan O'Brien in Milwaukee, Editing by Alex Dobuzinskis and Doina Chiacu)