Its confidence shaken, Saudi Arabia pledged anew to ensure stability in the kingdom and said Tuesday four of the militants behind a deadly assault on the U.S. consulate in Jiddah the day before were Saudis.

Analysts said Monday's assault — a strike on a highly guarded American target after Saudi Arabia had cracked down on militants — will likely encourage terrorists to attack again.

Five consulate employees, all non-American, were killed and another four were injured. The Interior Ministry on Tuesday named three of the assailants, none of whom appear on the kingdom's list of 26 most wanted militants. The ministry had said Monday there were five assailants, four of whom had been killed and the fifth captured. Tuesday, it specified only four as assailants, taking care to indicate it hadn't been determined how the fifth person, who was not identified, was involved.

The attack came a week after the deputy leader of Al Qaeda, Ayman al-Zawahiri (search), warned in a videotape that Washington must change its policies or face further attacks by the terror group.

Saudi and U.S. officials have blamed the terror network led by Saudi-born Usama bin Laden for all major militant attacks in the kingdom since May 2003.

The Saudi government has condemned the attack and Saudi Foreign Minister Prince Saud al-Faisal was reported to have called the U.S. Ambassador to Saudi Arabia, James Oberwetter.

"The kingdom is determined to root out terrorism and preserve its security and stability," the state-guided newspaper Okaz quoted Saud as telling the ambassador.

The attack in Saudi Arabia, the world's largest crude producer, along with unrest in Nigeria, also pushed crude prices upward Tuesday, as supply fears crept back into play and traders considered a potential production cut from oil cartel OPEC (search).

The attack's five victims were consulate staff: one Yemeni, a Sudanese, a Filipino, a Pakistani and a Sri Lankan, according to a Saudi security official speaking to Saudi television. He said 13 people were injured, including five Saudi security men.

The significance of the attack, analysts say, was the target, timing and element of surprise — three factors that may force a closer look at the Saudi government's efforts in fighting terror.

"Here is an American consulate that was targeted. It was penetrated. They managed to go through the security, which should have been as tough and as solid as a shield. It shows that American targets in Saudi Arabia, no matter how well protected, are vulnerable to these kind of attacks," said Abdul Khaleq Abdulla, an Emirates-based political analyst.

The consulate — like all U.S. diplomatic buildings and other Western compounds in Saudi Arabia — has been heavily fortified since last year's series of bombings against targets housing foreigners.

"This was a very hard target to attack, and they pulled it off. Whether Saudi security forces were lax, following their successes over the past few months, is debatable," said Diaa Rashwan, a Cairo-based expert on Muslim militants.

In Washington, State Department spokesman Adam Ereli said security measures were sufficient to allow employees to retreat to safe areas. No Americans were killed.

Whether or not the attackers accomplished their goal, analysts said the midday attack will boost the morale of extremist groups and raise questions about the effectiveness of the Saudi government's measures.

"This attack will encourage others to carry out similar attacks and will lift their morale after several setbacks," Rashwan said.

Saudi officials blamed the attack on "a deviant group," a description the government uses to identify extremists aligned with Al Qaeda.

Al-Jubeir said the attackers identified themselves as the Fallujah Brigade and that based on circumstantial evidence, including the choice of target and weapons, the group was likely aligned with one of Usama bin Laden's affiliates, Al Qaeda (search) in the Arabian Peninsula.

Attacks on Western targets in Saudi Arabia started in 2003, when car bombs hit three compounds housing foreign workers in Riyadh. Since then, the government has cracked down on Islamic militant cells and charities suspected of funneling money to terrorists.

In May, militants took over a resort complex in Khobar and held hostages for 25 hours, killing 22 people, including 19 foreigners.

In another attack that month, militants stormed offices of Houston-based ABB Lummus Global Inc. (search) in Yanbu, killing six Westerners and a Saudi. The attackers dragged the body of an American from the bumper of their car during a police chase.

Militants in Riyadh, the capital, also kidnapped and beheaded Paul M. Johnson Jr., an engineer for a U.S. defense company, in June.