Saudi authorities hunted Monday for three suspected Al Qaeda (search) militants who used hostages as human shields to escape after a weekend assault on a residential complex that killed 22 people, mostly foreign oil industry workers.

The attackers fled Khobar (search) to nearby Dammam, where they abandoned their truck for a car commandeered at gunpoint from an unidentified driver and drove off with police in pursuit, a police official said Monday.

A fourth militant — described as the ringleader — was captured Sunday after helicopter-borne Saudi commandos raided the upscale Oasis compound, where the gunmen had taken dozens of foreigners hostage in a hotel a day earlier.

On Monday, bloodstains, glass shards, bullet holes and evidence of grenade blasts scarred the sealed-off Oasis resort complex, according to an employee. Broken windows were visible in the upper floors of the hotel.

The official death toll from the entire 25-hour siege was eight Indians, three Filipinos, three Saudis, two Sri Lankans, an American, a Briton, an Italian, a Swede, a South African and a 10-year-old Egyptian. Twenty-five people of various nationalities were injured, and security forces evacuated 242 people from the Oasis, including residents not held hostage but trapped inside.

One of the militants also was wounded in the worst terror attack on Saudi soil in a year and the second this month to target its oil industry.

Thus far, the dozens of surviving hostages have kept away from the media, and Saudi authorities haven't provided many details on how the standoff ended. Saudi security stormed the building early Sunday after they found out that the hostages were being harmed, said Jamal Khashoggi, an adviser to Saudi Arabia's embassy in London.

"Intervention then became necessary," Khashoggi said.

An Interior Ministry statement said the three who escaped used hostages as human shields until they were able to commandeer a vehicle and flee, leaving the captives behind.

An Oasis employee who had been inside the heavily guarded compound assessing damage Monday, speaking on condition of anonymity, relayed an account from a freed hostage who was fluent in Arabic and who said security forces allowed the attackers to flee because they were killing hostages.

The former hostage said he heard a gunman say, "Let us go and we'll let the hostages go." Security forces first refused, but agreed after the militants, who also threatened to blow up the building, began killing hostages, the former hostage said.

A Saudi security official, speaking on condition of anonymity, would not directly address whether the militants were allowed to escape. But he said: "Our main priority was the hostages, and those guys who ran away, we know how to find them."

In the evening, several police cars surrounded a mosque next to a McDonald's in Khobar after police got word that suspected terrorists were inside the mosque. A policeman on the scene said two people had been detained on suspicion of having terrorist connections. He would not elaborate.

Lawyer Ibrahim al-Yami, whose office is across from the mosque, said he saw police take away the mosque's muezzin and his wife. Al-Yami said he heard one shot fired inside the mosque.

The attack began Saturday morning, when militants in military-style dress opened fire inside two oil industry office compounds. They then moved up the street to the Oasis.

Saudi commandos eventually freed 41 hostages, the Interior Ministry said. The Saudi ambassador to Britain, Turki al-Faisal, told the BBC that the commandos found bodies of nine hostages inside.

Nizar Hijazeen, a 32-year-old Jordanian software engineer who cowered in one of the hotel's rooms throughout the ordeal, said he saw five bodies scattered around the hotel after it was over.

"All the bodies appeared to have been shot," Hijazeen said.

A statement Sunday attributed to Al Qaeda's chief in the Saudi region, Abdulaziz Issa Abdul-Mohsin al-Moqrin, said the violence aimed to punish the kingdom for its oil dealings with the United States and to drive "crusaders" from "the land of Islam."

Saudi Arabia relies on 6 million expatriate workers to run its oil industry and related sectors.

The attack in the kingdom's oil industry hub was expected to have some effect on world oil markets, where prices have been at new highs, but analysts have said that jitters shouldn't be too strong since no hard oil facilities, such as refineries, were targeted.

Most oil markets were closed Monday, but one open in Tokyo indicated traders are concerned, with crude oil futures up, Dow Jones Newswires reported. Dow Jones also reported the attack prompted U.S. hedge funds, investment banks and speculators to sell the U.S. dollar, sending the currency to a 31/2-week low of 110 yen in Asian trading.

The U.S. Embassy in Saudi Arabia urged its citizens to leave the kingdom. Britain and Australia have warned their citizens that they fear further terror attacks may be imminent.

Four U.S. schools in the eastern province closed Sunday and Monday because of the violence, according to their Web sites.

Al Qaeda chief Usama bin Laden, blamed for past terror attacks in Saudi Arabia, has vowed to destabilize the Saudi kingdom for its close ties to the United States.

"The kingdom will stand with resolve before anyone who wants to damage its stability and security ... and affect the special relations it built with brotherly and friendly countries," King Fahd said in a statement released after the weekly Cabinet meeting Monday.

A suspected Al Qaeda attack on May 12, 2003, hit three Riyadh compounds housing foreigners, killing 26 people and nine suicide bombers. A high-profile crackdown on terrorists followed.

A previous attack targeted the offices of Houston-based ABB Lummus Global Inc. (search) in the western city of Yanbu on May 1, killing six Westerners and a Saudi.