RIYADH, Saudi Arabia (AP) -- Saudi Arabia pledged to hunt down attackers involved in a suicide car bombing that killed at least 17 people, while a senior U.S. diplomat said closer cooperation in the war on terrorism was needed to prevent more al-Qaida attacks in the kingdom.

Saudis blamed al-Qaida militants for the Saturday night attack and said it was proof of the terror network's willingness to shed Muslim blood in its zeal to bring down the U.S.-linked monarchy.

At least 13 of those killed in the explosion were Arabs, with four as yet unidentified, an Interior Ministry official told the official Saudi news agency. Five were children.

The attack at an upscale compound for foreign workers also wounded 122 people. The blast, not far from diplomatic quarters and the king's main palace, left piles of rubble, hunks of twisted metal, broken glass and a large crater.

President Bush joined other Western and regional leaders Sunday in expressing condolences and promising to stand by the kingdom in the fight against terrorism.

``On behalf of my nation I will just pledge that we will be fully participating partners if that is the desire of the kingdom of Saudi Arabia,'' said U.S. Deputy Secretary of State Richard Armitage, who arrived Sunday night in the Saudi capital.

Armitage, echoing initial Saudi assessments, said he was ``personally quite sure'' al-Qaida was behind the car bombing ``because this attack bears the hallmark of them.''

Such attacks appear to be directed ``against the government of Saudi Arabia and the people of Saudi Arabia,'' he said, adding that he expected more to follow.

Al-Qaida ``will prefer to have many such attacks to appear bigger than they are,'' he told a news conference. Such attacks showed that ``all of us have to work together.''

Armitage said he would discuss ``terrorism and counterterrorism cooperation'' and patching up strained U.S.-Saudi relations before leaving for Egypt on Monday.

He said the United States wanted ``to try to get back on a much more normal, congenial and beneficial'' path with Saudi Arabia, while expressing ``utmost faith'' in the leadership of Crown Prince Abdullah.

The blasts came after gunmen exchanged fire with security guards in a compound of about 200 houses. The attackers, believed to be in a police car, then drove into the compound and blew themselves up.

Most of the casualties were Lebanese. Four U.S. citizens were among the wounded, the ministry said. In Washington, State Department spokeswoman Amanda Batt said ``some Americans were treated for minor injuries and released.''

It still wasn't clear how many attackers there were or if they were listed as among the dead.

In comments published Sunday on the Web site of Saudi daily Okaz newspaper, Interior Minister Prince Nayef said he could not rule out a connection to suspected al-Qaida terrorist cells targeted in recent sweeps, as a number of suspects from those cells were still at large.

Dawood al-Shirian, a Saudi analyst, said the attackers had gone beyond terror.

``It's become a war on the regime, a war to turn the country into a new Afghanistan ruled by a Saudi-style Taliban,'' he said.

Adding to the al-Qaida connection was the similarity between Saturday's bombing and other attacks blamed on the terror network -- particularly the May 12 suicide car bombings of other Riyadh compounds housing foreigners, which killed 26 bystanders. Nine attackers also died.

Armitage also pointed to ``similarities to the May 12 attacks,'' and said ``some of the al-Qaida Web sites and things of that nature have been speculating about this type of event.'' He said he was unaware of any arrests, but praised Saudi cooperation in the war against terrorism as ``first rate.''

At the compound, located in a ravine surrounded by hills, residents trickled back Sunday mainly to salvage mementos, clothes, passports and other personal items.

Prince Nayef, the interior minister, toured the site and warned that authorities would pursue anyone who would attack the kingdom ``no matter how long the path is ... until we are completely certain that our country is free of every devil and every evil person.''

``No mercy or pity should be felt for anyone thinking of carrying out such acts,'' he said.

Al-Qaida, led by Saudi-born, fugitive multimillionaire Osama bin Laden, has long opposed the Saudi royal family, accusing it of being insufficiently Islamic and too close to the West, particularly the United States.

An anti-terror sweep launched after the May attacks has netted more than 600 extremists.

The attack also came as the kingdom is pushing social and legal reforms it has stalled for years and pursuing Islamic militants with a determination and openness Saudis have never seen. For decades, the government was reluctant to confront religious extremists, because it draws its legitimacy partly from the royal family's close association with the strict Wahabi Islamic philosophy.