At least one explosion and gunfire rocked a residential compound Saturday night in the Saudi Arabian capital, Riyadh, one day after the U.S. ordered its embassy there shut because of new terrorist threats, capping a week in which Saudi security forces clashed with anti-Western militants in the country.
At least four people were reported dead, but early estimates from the compound in the western part of the city suggested that more than 20 people may have been killed and scores more injured. The explosion occurred near the diplomatic quarter that houses the U.S. and other foreign embassies and the area where many senior members of the Saudi royal family live.
In Washington, State Department spokeswoman Amanda Batt initially said that up to three compounds "that house Westerners" -- but not diplomats -- had been attacked but later said that apparently only one compound was assaulted.
Batt said "it appears there were casualties" in the bombing. She said U.S. officials were investigating reports that one American was wounded and another was unaccounted for. Many American companies maintain a number of U.S. workers in the Saudi capital.
The official Saudi Press Agency described the attack as "a terrorist bombing." A Jordanian resident at the compound told Reuters he heard heavy gunfire before the explosion.
"I heard shots, many shots, and then one big explosion," said the resident, who identified himself only as Alaa. "Many villas were damaged -- four or five even collapsed. My house was far away, but my windows were shattered."
The explosion was reminiscent of the May 12 blasts in three Riyadh neighborhoods known to house Americans and other Westerners that killed 35 people, including the nine bombers.
Like the earlier assaults, the new attack came on the heels of a crackdown on militants by Saudi forces and appeared aimed at punishing the Persian Gulf state for cooperating with U.S. anti-terrorism efforts. And like them, U.S. intelligence officials said, the new blast was preceded by an increase in "chatter" among militant groups throughout the Gulf region.
U.S. concern rose Thursday after a Saudi raid on a reputed terrorist cell in Mecca that turned into a shootout between Saudi authorities and suspected terrorist operatives. Two suspected militants blew themselves up, apparently to escape arrest, after a third was killed in the shootout. Authorities also clashed with suspected militants Monday in Mecca.
U.S. officials had worried that the Mecca raid might prompt the operatives who escaped to speed up previously planned attacks -- as they apparently did in May, when militants set off the blasts only days after an intense firefight between Saudi police and suspected members of an Al Qaeda cell.
"Some associates [of the] cell that was taken down [in May] were involved in the attack a couple days later," a U.S. official said. "They may have sped up the [execution of their plans]. It was not a coincidence."
Even before Thursday's raid in Mecca, U.S. officials had worried that militants might be planning a wave of attacks during Ramadan, the Muslim holy month. They noted that assaults and bombings often occur in the wake of recorded messages from Al Qaeda leader Osama bin Laden, the latest of which -- an audiotape calling for bold new attacks against the United States -- surfaced last month.
The State Department reacted to the combination of warnings Friday by shutting down the U.S. Embassy in Riyadh and two consulates elsewhere in Saudi Arabia.
In Riyadh, the U.S. Embassy said it had received intelligence that terrorists were planning attacks in the Gulf state. It warned Americans to be "vigilant when in any area that is perceived to be American or Western."
A State Department warning to Americans traveling in the Gulf region said U.S. intelligence "continues to receive indications of terrorist threats aimed at American and Western interests, including the targeting of transportation and civil aviation. There is credible information that terrorists have targeted Western aviation interests in Saudi Arabia. American citizens in Saudi Arabia should remain vigilant, particularly in public places."
Reports about Saturday's attack remained sketchy. U.S. and Arab news services reported that at least one -- and perhaps as many as three -- explosions rocked the so-called B2 compound. The neighborhood of 200 villas has in the past housed Boeing Corp. workers, but the U.S. aircraft maker has scaled back its Saudi operations. The compound is reportedly now home to Arab workers and some non-U.S. Westerners.
Compound resident Rabie Hadeka told Al Arabiya TV that "about 20 to 30 people have been killed and 50 to 60 injured." Al Arabiya later reported that at least four people had died.
Hadeka said in a telephone interview with the television channel that "around 10 buildings collapsed and shattered. Glass was spread everywhere."
The streets of the compound and the nearby Muhaya shopping center were reportedly crowded with people because of Ramadan, when Muslims are expected to fast during the day and so socialize and shop after nightfall.
Some reports suggested that many victims were women and children. Resident Bassem Hourani told Al Arabiya: "I heard screams of the children and women. I don't know what happened to my friends or whether any of them was injured."
A woman living in the compound told Associated Press that "there is a lot of blood" at the scene of the explosion. "I am extremely terrified," she said. "I felt it was an earthquake."
There were conflicting reports about how close the attack came to the U.S. Embassy. Some suggested the blast was three miles from the embassy, while others described them as much closer. The Arab News reported that Saudi security forces were out in large numbers after the attack and had ringed the diplomatic quarters.
Like the May bombings, the new attack outraged the Saudi government.
"These people have targeted Muslim and Arab people, innocent people. They are trying, really, to give the impression that they can target any place in order to show that the government can't protect its citizens," one Saudi aide said. "The government is pressing them, and everyone in the kingdom who detests their tactics is gathering force to fight them."
The aide, who spoke on condition of anonymity, said the latest attack would not weaken Saudi cooperation with U.S. anti-terrorism efforts.
"We are very committed, either together or individually, to fight terrorism in all its forms," the aide said. "We are working together with the U.S. The U.S. knows that."
Times staff writer Doyle McManus contributed to this report.