The usually balmy US south has been paralysed by a freak snowstorm that forced children to shelter in schools overnight and prompted officials across the region to issue emergency declarations.

Schools remained closed in many localities across the south on Wednesday, as authorities struggled to shake off Tuesday’s unaccustomed snowfall and freezing temperatures.

Temperatures in Atlanta fell to minus 10C, the coldest in memory for many residents.

Emergency declarations were issued in several southern states, as a result of the wintry conditions felt as far south as Texas and affecting Florida, Alabama, South Carolina and other states famous as havens from the northern winter.

Television footage early on Wednesday showed traffic still snarled in many places, more than 24 hours after the backups began forming.

Hundreds of traffic accidents were reported across the region , including several involving lumbering yellow school buses that slid off ice-slickened roads.

News reports said officials were still trying to rescue motorists stranded on the sides of roads, many of whom had been forced to tough out the night in their vehicles.

The snowfall was heaviest as schools were letting out for the day, and as workers were fleeing downtown offices.

Atlanta Mayor Kasim Reed pleaded with residents stay off the roads on Wednesday to give officials the ability to resolve lingering crises from Tuesday’s disastrous commute.

“We urge the public to stay home as much as possible today to allow our crews to make our roads safe, passable and fully open for business as soon as possible,” said Reed, adding that the first priority for city officials “is ensuring the safety of all residents.

Some area residents were incensed that the government did not have the foresight to cancel classes ahead of the start of the school day.

“Kids are still stranded in some schools here in Atlanta,” one Twitter user wrote, showing a photo of an auditorium filled with elementary school kids watching movies on a giant screen.