Most of the victims are believed to be children - as rescuers search for survivors of the tragedy near the Dead Sea.
Rescuers are searching today for survivors of a flash flood in Jordan that killed at least 21 people - most of them children aged 11 to 14 who were on a school bus.
The students, their teachers and other adults had stepped out of the vehicle when the water swept them towards the nearby Dead Sea, said officials.
The children were in a tourist area called Al-Miyah al-Sakhina after being on an outing yesterday.
"Heavy rains caused a flash flood close to the Dead Sea that washed away a school bus carrying 37 students and seven minders," said a fire service official.
Prime Minister Omar Razzaz said it appeared the school had broken education ministry regulations that banned trips to the area due to bad weather.
But an official at Jordan's education ministry said the school had received permission around a week ago to visit Al-Azraq, the site of a nature reserve east of Amman.
The Dead Sea is the lowest point on earth and is surrounded by steep valley slopes that often see flash floods and landslides. Climate change experts warned last year that an increase in sudden and extreme weather conditions meant Jordan will face more flash floods and unexpected frosts.
A bridge on one of the Dead Sea cliffs had collapsed because of the heavy rain - the first major downpour after the end of the summer season. Many parts of Jordan were hit by flooding.
Israel's military said it was helping with the operation, sending helicopters and forces specialised in search and rescue.
Dozens of people were rescued but eight are still missing. One hospital treated 43 survivors with injuries.
Government spokeswoman Jumana Ghneimat told state television that "tonight, every household in Jordan is sad, it is a tough and painful night for all Jordanians".
Ironically, Jordan is the fourth driest country in the world and its access to fresh water has fallen dramatically in recent years. A report in August said climate change could double the number of droughts by 2100.
Last month, a flash flood that swept through a primary school in Indonesia killed 17 students.
Floods in India's Kerala state in August affected 650 schools and left 1.4 million homeless. Last year floods destroyed or damaged thousands of schools in India, Bangladesh and Nepal.