Violent storms battering the central-eastern United States have killed at least 16 people, officials have said, with the National Weather Service warning of "severe" flash flooding in the coming days.

A line of fierce storms on Saturday, stretching from Arkansas to Ohio, damaged buildings, flooded roadways, and produced dozens of tornadoes.

Tennessee was hardest hit by the extreme weather, with state authorities saying on Saturday that 10 people had died across the western part of the state.

Two people were killed due to floods in Kentucky, according to state Governor Andy Beshear, including a child who was "swept away by floodwaters".

"Severe, widespread flash flooding is expected" into Sunday in parts of the central-eastern region, the National Weather Service (NWS) said, warning that "lives and property are in great danger."

Two storm-related deaths were recorded in Missouri and one in Indiana, according to local media reports and authorities.

A five-year-old was found dead in a home in Little Rock, Arkansas, "in connection to the ongoing severe weather", the state's emergency management agency said in a statement.

"Flooding has reached record levels in many communities," Kentucky's Governor Beshear wrote on social media Saturday, urging residents in the state to "avoid travel and never drive through water."

More than 100,000 customers were without power in Arkansas and Tennessee as of early Sunday, according to the tracking website PowerOutage.us.

The NWS on Saturday said that moderate to severe tornadoes could form in parts of the Tennessee Valley and Lower Mississippi Valley on Sunday, along with "severe thunderstorms".

Scientists say global warming is disrupting climate patterns and the water cycle, making extreme weather more frequent and ferocious.

Last year set a record for high temperatures in the United States, with the country also pummelled by a barrage of tornadoes and destructive hurricanes.