US President Joe Biden declared Kentucky a disaster area after the hurricane that struck it, and left massive destruction, at a time when the authorities fear that the number of deaths may exceed 100.

Biden described the wave of hurricanes, one of which cut more than 200 miles (320 km), as "one of the largest" storms in American history.

"It's a tragedy," Biden said, moved, in televised comments, pledging support for the affected states.

"We still don't know the amount of loss of life and the full extent of the damage," he added.

Rescuers in the US state of Kentucky searched the rubble for any survivors, while many residents whose homes were destroyed, without electricity or water, salvaged what could be saved after a series of powerful tornadoes that officials fear have killed more than 100 people and destroyed homes and businesses.

Authorities said they had no hope of finding survivors after tornadoes swept through the Midwest and the American South on Friday night, killing at least five states.

Six workers were killed at an Amazon warehouse in Illinois after the factory collapsed due to the force of the hurricane.

Hurricanes that hit the American states caused massive damage (Anatolia)

Hurricanes swept through a nursing home in Arkansas, killing one of two people who died in that state.

Four deaths were reported in Tennessee and two in Missouri.

Mayfield

But the areas hardest hit were the small town of Mayfield, Kentucky, where severe tornadoes, which meteorologists say are unusual in winter, destroyed a candle factory, fire stations and police.

Mayfield Mayor Cathy Onan said the western Kentucky town had been reduced to "a rubble."

"There is always hope" to find survivors among the missing, Onan said in a statement to "NBC" (NBC) on Sunday, adding, "We hope for a miracle in the coming days."

Officials have described the town of 10,000 people as a "wasteland." The city has been razed to the ground, historic homes and buildings have collapsed, tree trunks have been stripped of their branches, and overturned cars have strewn across the fields.

Volunteers were keen to provide food needs for those affected by hurricanes (Reuters)

Kentucky Governor Andy Bashir said at least 80 people had died in his state and that the death toll would eventually exceed 100, but he was hopeful for "some miracle".

These were the most destructive tornadoes in the state's history, Bashir said, as even the sturdiest buildings of steel and bricks were flattened.

More than 300 National Guard personnel moved from house to house and removed the rubble, and teams worked to distribute water and electricity generators.

The US Federal Emergency Management Agency has opened shelters, sending teams and supplies of meals and water.

The hurricane that hit Kentucky touched the ground more than 200 miles (320 km), which is one of the longest distances since the record of the hurricane track began.

Officials confirmed that hurricanes and storms flattened hundreds of buildings (Reuters)

The longest-tracked US hurricane was a storm that extended 219 miles in Missouri in 1925, killing 695 people.

Reports put the total number of cyclones in the area at 30.