In its first such attack, Al Qaida has succeeded in penetrating a U.S. consulate in Saudi Arabia and holding the facility for several hours.

The attack came one week after Al Qaida leader Ayman al-Zawahri, warned in a videotape that Washington must change its policies or face further attacks by the terror group.

U.S. officials said five Al Qaida operatives, employing light weapons and grenades, blasted their way into the U.S. consulate in Jedda on Monday and took over the compound for about three hours.

They said Al Qaida insurgents, who arrived at the consulate gate in two vehicles, killed at least five people before Saudi commandos stormed the consulate and killed most of the attackers, Middle East Newsline reported.

"There was a breach of the perimeter," State Department deputy spokesman Adam Ereli said. "Yes, that's going to be looked into."

This was the first time Al Qaida had succeeded in capturing a U.S. diplomatic facility in Saudi Arabia.

For months, U.S. officials warned that Al Qaida was planning a major attack on a Western diplomatic facility in Jedda, a port city with about 9,000 Americans, most of whom were employed in the kingdom's defense and energy sector.

Over the last year, security at the U.S. consulate in Jedda has been upgraded, officials said. Security measures included the construction of a fortified guardhouse and installation of infrared cameras.

"There are security enhancements at this consulate, that were important in preventing the vehicle from getting on the compound," Ereli said.

On Tuesday, all U.S diplomatic facilities in Saudi Arabia were closed as officials reviewed security arrangements. The United States maintains an embassy in Riyad and consulates in Dhahran and Jedda.

U.S. officials said five consulate employees, including a security guard, were killed. One American staffer was injured in the shootout. On Tuesday, Al Qaida claimed responsibility for the Jedda attack.

Officials said at least five Al Qaida insurgents entered the consulate on foot through a side gate at around 11 a.m. local time. They said consulate officials quickly spotted the attackers and secured entrances to the consulate building.

"Because of security measures in place, they were unable to penetrate that building," Ereli said. "The Marine security guard detachment and the regional security officer assigned to the consulate general took defensive measure to protect the employees on the compound at that time, alerting them to the attack and moving them to safe haven areas."

The Saudi Interior Ministry said three of the five attackers were killed when Saudi commandos stormed the consulate. Two others were captured. The ministry said there were no casualties among Saudi security officers.

Earlier, witnesses and Saudi security sources said four National Guards officers were killed in the initial assault. But a spokesman for the Saudi embassy in London later said two security officers were critically injured and another two sustained light injuries.

Interior Ministry spokesman Brig. Gen. Mansour Al Turki said the insurgents slipped past the consulate gates when they opened for a U.S. embassy car. Al Turki said the assailants hurled grenades and captured the control booth at the gate. At that point the insurgents lobbed incendiary grenades that caused heavy smoke.

Adel Al Jubeir, foreign affairs adviser to Saudi Crown Prince Abdullah Bin Abdul Aziz, gave another account. He said in a telephone briefing from the Saudi embassy in Washington that Al Qaida insurgents approached the consulate in two vehicles. When the first car was stopped by Saudi guards, the occupants of both vehicles stormed the gate, hurling grenades and firing semi-automatic rifles.

Some of the Al Qaida operatives then grabbed 17 people waiting at the visa area while others hurled grenades toward the U.S. Marine barracks. Witnesses told Saudi newspapers that the insurgents appeared well-trained and kept Saudi security forces at bay for three hours.

At one point, the attackers called a police station in Jedda and warned that the hostages would be killed unless Saudi security forces withdrew. By that time, Saudi commandos, dropped into the courtyard by helicopter, overpowered the insurgents. Al Jubeir said the Saudi assault was coordinated with U.S. Marines, who were securing the consulate building.