Saudi King Abdullah on Monday ordered an inquiry into the catastrophic flash flood in Jeddah last week that killed at least 106 people and sparked a rare burst of public outrage.

The SPA state news agency said he also ordered that one million riyals (267,000 dollars) in compensation be paid to each family of the victims, many of whom drowned or were crushed in cars by what witnesses called "a tsunami."

Prince Khalid bin Faisal, governor of the Mecca region which includes Jeddah, will head the inquiry, assess personal and property losses and establish if anyone bears any responsibility.

"We are aware that we cannot overlook the fact that there are errors or omissions from certain quarters" that must be "disclosed and dealt with firmly," the king's decree said.

The flash flood struck the Red Sea port on Wednesday while the authorities were focused on caring for 2.5 million hajj pilgrims in Mecca 80 kilometres (50 miles) to the east.

Witnesses described a wall of water several metres (yards) high sweeping over busy roads, destroying homes and sweeping away hundreds of cars and huge trucks.

Unofficial estimates put the damage in the hundreds of millions of dollars.

The inability of the city's infrastructure to handle the flood and the poor reaction of some officials to the disaster sparked a never seen before wave of open criticism of the government on the Internet.