King Abdullah also cancelled a trip to Bahrain to follow the rescue operations, Petra reported.
"My sadness and sorrow are matched only by my anger at anyone who did not take the steps that could have prevented this painful incident", the king wrote on Twitter. "My condolences to the families of the deceased, myself, and all Jordanians". The pain and suffering of every family is my own pain and suffering as well.
A complex rescue operation involving helicopters, divers, sniffer dogs and hundreds of searchers had continued into the night Thursday and then resumed after daybreak on Friday.
At least 35 people were injured and a nearby bridge also collapsed, according to local media reports. Few imams were willing to lay blame. The spokesman said the students were from a middle school.
Relatives gather outside a hospital near the Dead Sea, Jordan.
Pressure grows on Saudi Arabia
Saudi Crown Prince Mohammed bin Salman has called the son of Jamal Khashoggi to express condolences, the kingdom has announced. Saudi Arabia's Foreign Minister formally acknowledged on air that the killing of Khashoggi was a "tremendous mistake".
"It swept away the students for 4 to 5 kilometres, " some as far as the Dead Sea, he said.
Jordanians on social media and radio derided the school, even flooding its Facebook page with comments such as "school or graveyard?", calling its administration "reckless" and warning that "the fate of these children and what they had suffered will haunt you to your graves".
He reportedly instructed state agencies to provide all needed assistance to ensure the safety of the students.
"Though the final cause of death was drowning, all of the victims however suffered from broken bones and other injuries because they were hit by huge boulders as they were being swept away by the flash flood", he told Al Jazeera.
Education Minister Azmi Mahafzah promised a "full inquiry" into the school children´s deaths. The decision, which is awaiting the outcome of initial police and parliamentary investigations to the Dead Sea tragedy, is expected within days, sources confirmed. But its arid conditions and its deep canyons make it susceptible to flash floods.
The Dead Sea, the lowest point on the earth, is surrounded by steep valley slopes that frequently witness flash floods and landslides.