Saudis expect another attack any time
Kingdom orders 4,600 troops to Mecca for Ramadan security
Destroyed vehicles can be seen Sunday at a devastated Riyadh housing complex.
CNN's Nic Robertson on Saudi security officials' anticipation of another terrorist attack.
RIYADH, Saudi Arabia (CNN) -- Saudi security officials expect another terrorist attack at any time and ordered 4,600 troops Sunday to the holy city of Mecca to provide additional security until Ramadan is over, government sources said.
The death toll from Saturday night's suspected al Qaeda attack on a residential compound in Riyadh rose to 17 on Sunday, including five children, the Saudi Interior Ministry said. More than 110 were wounded, and government sources said as many as 25 may have died.
Meanwhile, 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 devastated compound.
"All those who are propelled to do these acts must stop or surrender because it would be better for them and their salvation. There is no crime more heinous than this."
The attackers stormed the affluent neighborhood near Riyadh's diplomatic quarter late Saturday, first firing on security guards and then driving their explosives-laden cars through the gates.
Sources said the attackers apparently had stolen a jeep from Saudi security forces to disguise themselves. Saudi guards opened the gate upon seeing the jeep before the attackers opened fire, the sources said.
The subsequent explosions destroyed much of the neighborhood and killed or wounded dozens of residents, journalists and officials in Riyadh said. The compound is thought to have housed mainly Arab expatriates.
Westerners who work in Saudi Arabia are considering sending their families home because of the dangers there and moving their companies out of Saudi Arabia until it becomes more safe, some Western businessmen told CNN.
In Washington, President Bush expressed his condolences to Crown Prince Abdullah and told him the United States stands with Saudi Arabia in the war against terrorism.
U.S. Deputy Secretary of State Richard Armitage arrived Sunday in Saudi Arabia from Iraq and met with the crown prince.
Prince Bandar, Saudi ambassador to the United States, issued a statement from Washington calling the attack a "cowardly act" of terrorists.
"We are driving them out of their hiding places, we are killing and capturing their leaders, and we are choking off their means of support," Bandar said. "As a result, their actions grow more desperate and more heinous.
"The attack and subsequent murder of innocents took place during the holy month of Ramadan, which is a month for contemplation and prayer, and for remembering those less fortunate. This proves that the terrorists have no respect for the principles of Islam, humanity or decency."
The attack came a day after the United States said it was shutting its embassy and consulates in Saudi Arabia, citing intelligence of an imminent terrorist attack.
A senior official in the Saudi Interior Ministry said his government was certain the attack had been planned and carried out by al Qaeda.
Officials are citing crucial similarities with a car bombing in the city May 12 that killed 23 residents and 12 attackers.
The blasts ripped through a complex housing mainly Arabs.
Saudis, Egyptians, a Sudanese and an Indian were among the dead, according to the Saudi Press Agency.
The wounded comprise 19 nationalities, the agency said: 53 Lebanese, 17 Egyptians, four Americans with dual citizenship from other Arab nations; and six Canadians, five of whom are originally citizens of Arab countries. Twenty-five of the wounded remain in hospitals.
Other casualties were from Saudi Arabia, Sudan, Eritrea, Jordan, Indonesia, Bangladesh, Ethiopia, the Philippines, Syria, the Palestinian territories, Pakistan, Turkey, Sri Lanka and Romania.
The Interior Ministry official said the timing of the attack -- with many people away from their homes observing Ramadan -- averted a higher death toll.
Other officials said many of the wounded were children, left home while their parents were gone.
State Department spokeswoman Amanda Batt said the U.S. Embassy in Riyadh reported that some Americans were treated for minor injuries and have been released.
Because U.S. citizens are not required to register, it was possible that unregistered Americans may have been at the compound when it was attacked, a U.S. official said.
Saudi business sources told CNN the compound is a mile or so from the homes of several top members of Saudi Arabia's ruling family.
CNNArabic.com editor Caroline Faraj and correspondent Nic Robertson contributed to this report.