Wave of tornadoes kill 18 in US

Tornadoes killed at least 18 people in Alabama last night, including 15 at a high school where students were trapped under a collapsed roof, state officials said.

Two died elsewhere in Enterprise yesterday and one in rural Millers Ferry, where a separate apparent twister wrecked mobile homes, Alabama Emergency Management Agency spokeswoman Yasamie Richardson said.

"The number could very well increase as the search effort continues through the night," she said.

More than 50 people were taken to hospital as the violent storm front crossed the state.