Photo taken on Dec. 11, 2021 shows a heap of rubble after tornadoes in Mayfield, Kentucky, the United States.Photo:Xinhua

 

Photo taken on Dec. 11, 2021 shows a tree toppled in tornadoes in Mayfield, Kentucky, the United States.Photo:Xinhua

 

Photo taken on Dec. 11, 2021 shows a heap of rubble after tornadoes in Mayfield, Kentucky, the United States.Photo:Xinhua

 

Photo taken on Dec. 11, 2021 shows houses damaged in tornadoes in Mayfield, Kentucky, the United States.Photo:Xinhua

 

A man walks past a heap of rubble after tornadoes in Mayfield, Kentucky, the United States, on Dec. 11, 2021.Photo:Xinhua

 
Death toll may rise to 100 after at least 30 tornadoes swept through six states overnight in the central parts of the United States, including Arkansas, Mississippi, Illinois, Kentucky, Tennessee and Missouri.

A candle factory in Kentucky has been completely destroyed, local media reported on Saturday.

"There were about 110 people in it (candle factory) at the time that the tornado hit it," Kentucky Governor Andy Beshear said. "We believe our death toll from this event will exceed 50 Kentuckians and probably end up 70 to 100."

Beshear has declared a state of emergency in the area.

Tornadoes also hit a nursing home in Arkansas and took off the roof of an Amazon warehouse in Illinois, causing certain fatalities. Another nursing home and a fire station in Trumann of Tennessee also caused substantial damage.

It was the worst tornado that touched down in northeastern Arkansas and stayed on the ground for about 223 miles into Kentucky, and most likely the longest reported tornado in history, local media reported.

According to PowerOutage.US, at least 331,549 utility customers in four states were left without power.

Issuing tornado warning on Friday, the National Weather Service said at least 25 million people were under threat from massive thunderstorm systems.