At least 18 people died and 35 were injured in an area near the Dead Sea, in the west of Jordan, as a result of flooding caused by torrential rains in the country on Thursday, according to the Jordanian Department of Civil Defence.
"The students were on a school trip and it appears that a mudslide along the road swept their bus away", the official added.
The official news agency Petra said 37 students, along with seven adults, had been touring near the Dead Sea when heavy rains unleashed flash floods in the area.
The flooding carried people for "four to five kilometres", Sharaa said, while some survived by clinging to rocks.
Troops were helping to locate those missing despite adverse weather conditions, a statement said.
The Beirut municipality cautioned residents to take necessary precautions, saying heavy rains and flooding could block streets and damage properties in the capital, the Daily Star newspaper reported.More news: Trump accuses Saudi Arabia of lying on Khashoggis death
The Israeli military said that, following a request from the Jordanian government, it had sent a number of helicopters with soldiers from an elite search and rescue unit.
Prime Minister Omar Razzaz is now overseeing part of the rescue operation and visiting the injured.
"Most of the dead were schoolchildren aged 11 to 14 who were taking part in a school trip to the Dead Sea region" when their bus was swept away by floodwaters.
The search for survivors continued after daybreak, with helicopters and teams with sniffer dogs scouring the rocky slopes near the Dead Sea in the Jordan Valley.
Jordanian rescuers searching the Dead Sea area for survivors of flash floods found the body of a 12-year-old girl on Friday, raising the death toll in the tragedy to 19. The Dead Sea, the lowest point on earth, divides Jordan from Israel and the West Bank.
Civil defence spokesman Captain Iyad al Omar told Reuters the number of casualties was expected to rise.