At least 18 people, mainly schoolchildren and teachers, were killed on Thursday by a flash flood during a school outing near Jordan's Dead Sea in one of the worst disasters in the kingdom in years, rescuers and hospital workers said.

Thirty-four people were rescued in a major operation involving police helicopters and hundreds of army troops, police chief Brig. Gen. Farid al Sharaa told state television. Some of those rescued were in a serious condition.

Many of those killed were children under 14. A number of families picnicking in the popular destination were also among the dead and injured, rescuers said, without giving a breakdown of numbers.