Seven people were injured, including two critically, when a possible tornado touched down at 4 a.m. in Springdale, a city in northwest Arkansas, Mayor Doug Sprouse said in a Facebook post.

“Many residents have been displaced from their homes and numerous businesses have reported significant damages,” he said, adding there have been no reported deaths.

The southeastern part of the city sustained significant damage, local authorities said. They announced road closures following reports of downed power lines, trees and traffic lights.

Video obtained from CNN affiliate KHBS/KHOG showed flattened buildings, roof damage and yards littered with storm debris. At George Elementary School, the gym was destroyed and the kitchen and cafeteria were severely damaged, the Springdale School District said. There were no students inside the school at the time, Gov. Asa Hutchinson said on Twitter.The damage stemmed from a line of storms that raced across eastern Oklahoma and western Arkansas and intensified throughout the day. By late afternoon, at least 38 million people were still at risk for life-threatening extreme weather, largely across the Southeast.Severe thunderstorms were expected later in the day and into the night over parts of the lower Mississippi Valley and the mid-South, into the central Gulf Coast states, the Storm Prediction Center (SPC) said.

The rainfall could lead to flash flooding over parts of Louisiana and Mississippi, the Weather Prediction Center said.

As the storms rolled through the region, more than 140,000 customers were left without power Wednesday evening, with the majority in Mississippi, Alabama and Tennessee, according to PowerOutage.us.

The greatest concern is for tornadoes

As of Wednesday afternoon, tornadoes were the greatest concern from the storms — with the possibility of twisters of at least an EF-2 on the Enhanced Fujita Scale — as well as damaging wind gusts, the SPC said. EF-2 tornadoes can cause considerable damage, ripping roofs from houses and destroying mobile homes. The SPC issued at least seven tornado watches Wednesday. Those that remained active included a tornado watch issued until 10 p.m. CDT for parts of Kentucky, Illinois, Missouri and Indiana, an area that includes the town of Mayfield, Kentucky that was devastated by a tornado in December.

There was also a tornado watch across central Tennessee and much of Alabama until 1 a.m. CDT Thursday and another watch for southeast Mississippi, and parts of southern Alabama and the Florida Panhandle until 4 a.m. CDT.

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A moderate risk – level 4 of 5 — for severe storms covered Mississippi and included portions of Arkansas, Louisiana, Alabama and Tennessee, and Florida. In addition to Jackson, cities like Memphis in Tennessee, Baton Rouge in Louisiana, and Mobile and Montgomery in Alabama…

Source: Possible Arkansas tornado injured 7 as more potential twisters and severe weather threaten Southeast