JIDDAH, Saudi Arabia – Lobbing grenades, insurgents invaded Jiddah’s heavily guarded American Consulate yesterday, attacking staffers and others in the compound until Saudi security forces stormed in. Nine people, none American, were killed in the attack, which was claimed by Al Qaeda and showed how vulnerable Saudi Arabia remains to Islamic extremist violence.

The bold assault, the worst in the kingdom since May, suggested that a fierce crackdown waged by Saudi security forces has not completely put down Al Qaeda in the native land of terror leader Osama bin Laden.

The group Al Qaeda in the Arabian Peninsula said the attack was part of its “war on the crusaders and the Jews….[aimed at] getting them out of the Arabian peninsula. The Mujahedeen are continuing on their path…they will not weaken…but will be patient.”

In a statement posted on an extremist Web site, the group said the attack had been named “the blessed Fallujah battle,” referring to the former insurgent stronghold in Iraq invaded last month by American troops. It also said it was carried out by the “unit of the martyr Abu Anas al-Shami,” who was a spiritual adviser to Abu Musab al-Zarqawi, the most feared terrorist in Iraq. There was no way to confirm the claim.

President Bush said the attack showed “terrorists are still on the move,” trying to intimidate Americans and force America to withdraw from Saudi Arabia and Iraq. The American Embassy in Riyadh and the consulate in Dhahran were closed to the public for two days, as was the Jiddah consulate. The Embassy urged the thousands of Americans in the country – many of whom already live under extraordinarily tight security – to “exercise utmost security precautions.”

Yesterday’s assault began when the attackers sneaked on foot behind an embassy car that was entering the consulate through a gate, then lobbed grenades at guards to take control of the gate area, said Brigadier General Mansour al-Turki, the Interior Ministry spokesman. The attackers also used incendiary grenades designed to create fires and to send up heavy smoke, he said.

Plumes of black smoke could be seen rising in the air shortly after the attack. About 20 minutes after fighting their way in, the attackers telephoned emergency services, claimed to be holding up to 17 people hostage and warned Saudi forces not to attack, said the foreign affairs adviser to Crown Prince Abdullah, Adel al-Jubeir.

Those held at gunpoint were mostly either in the courtyard like area to apply for visas, or were employees who worked in that area, a senior Saudi official in Washington said.

As the call was ending, Saudi security forces stormed the area and fought a short gun battle, the official said. Mr. al-Jubeir said the fight was over within three or four minutes, and the troops then worked for about three hours after that searching the compound to ensure it was secure. He denied earlier reports that the standoff lasted four hours.

Employees rushed into a safe area, and the attackers never made it inside the consulate’s buildings, General al-Turki said. He denied anyone was held hostage, but said the attackers did hurt those they came across in the courtyard area.

Five consulate employees, all non-Americans, were killed and another four injured, the State Department said. Three of the five attackers also died in the shootout and the other two were captured wounded, the Saudi Interior Ministry said.

A Saudi security official, quoted on Saudi TV station al-Ikhbariya, said one of the wounded attackers later died in custody. The official said that besides the attackers, the five dead were a Yemeni, a Sudanese, a Filipino, a Pakistani, and a Sri Lankan. The official said 13 people were wounded, including five Saudi security men.

“We could hear the gunshots outside, but we didn’t know what was going on,” said a consulate employee who rushed to the safe area and later said by telephone on condition of anonymity.

Mr. al-Jubeir said officials had suspected an attack was coming. “We had indications that led us to increase the level of alert and to beef up security in Jiddah and in other areas,” said Mr. al-Jubeir, noting the government was at a higher threat level.

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

Saudi officials blamed the attack on a “deviant” group – the government’s way of identifying Al Qaeda extremists it holds responsible for a string of terror strikes over the past two years.

Saudi and American officials have blamed Al Qaeda, led by Mr. bin Laden, for all major extremist attacks in the kingdom since May 2003.

The Saudi government has cracked down hard, arresting and killing many key rebels, and quieting the attacks somewhat. But in May, 22 people were killed, including 19 foreigners, by insurgents who took over a resort complex in Khobar and held hostages for 25 hours.

In June, rebels in Riyadh, the capital, kidnapped and beheaded Paul Johnson Jr., an engineer for an American defense company. Yesterday’s attack showed that extremists are still capable of carrying out sophisticated strikes despite the government crackdown.

“This was a very hard target to attack, and they pulled it off,” said Diaa Rashwan, a Cairo-based expert on Muslim extremists, predicting the attack would boost morale among extremists. “For the government, this was a security failure. For the militants, this was a military victory.