The toll from the suspected Al Qaeda attack in a residential compound in Riyadh rose to 17 on Sunday, the Saudi interior ministry said.
Fearing another attack, 4,600 troops were dispatched to Mecca on Sunday to provide additional security until Ramzan was over, government sources said.
The government pledged to track down those behind the attack.
"We will get the perpetrators no matter how long it takes," Interior Minister Prince Nayef told Saudi state television as he inspected the compound.
The attackers stormed the compound late Saturday, first firing on security guards and then driving their explosives-laden cars through the gates.
The attackers apparently had stolen a jeep from Saudi security forces to disguise themselves, CNN quoted sources as saying.
An Indian was said to be among those killed. But there was no confirmation from the Indian embassy.