US officials were Thursday monitoring a nuclear plant in the southern state of Alabama that lost power amid severe storms that swept through the region.

The US Nuclear Regulatory Commission (NRC) said the Browns Ferry nuclear power plant near Athens, Alabama "lost offsite power early Wednesday evening due to severe storms that damaged power lines in the area."

The plant automatically shut down after losing offsite power and operators from the Tennessee Valley Authority are working to restore that supply, said the NRC, stressing the plant's "safety systems have operated as needed."

The historic storms that slammed the region on Wednesday left at least 190 people dead, killing 128 people in Alabama alone with tornados and floods ripping a trail of destruction across the state.