Saudi Arabia's civil defence said Thursday that 77 people were killed in intense flooding in Jeddah and nearby areas, and that scores could still be missing.
Jeddah civil defence spokesman Abduallah al-Omary said most of the deaths occurred in vulnerable areas in the city's eastern and southern districts after a downpour on Wednesday.
Many of the dead were in automobiles and buses caught up in the rising waters, according to witnesses.
Based on calls from worried locals, 351 people were missing, Omary said.
In some areas roads were still under more than one metre (three feet) of water on Thursday.
"The water has gone down and things are getting better today compared to yesterday. We are doing our best to make things easier for the people still stuck," he said.
A 90-millimetre (3.5-inch) downpour hit the Red Sea city and its surroundings, flooding roads and tunnels and collapsing some older buildings and homes.
At least four of the dead were in the neighbouring province of Mecca, where some 2.5 million pilgrims are undertaking the annual hajj.
However, no hajj participants were killed in the floods, a health ministry official said.