Saudi officials are blaming a group of al Qaeda militants for an attack on the U.S. consulate in the city of Jeddah that left at least eight people dead.

That total includes five members of the consulate's local staff, and three of the five attackers.

In a statement carried by the Saudi Arabia Press Agency on Monday, the Saudi Interior Ministry said the other two attackers had been injured and arrested in a gun battle following the attack.

Yahya Hamidaddin, an eyewitness to the battle between the militants and U.S. marine embassy guards, said: "There's so much security around the compound. How could anyone do this, to be able to pull it off?"

U.S. officials are asking themselves the same question.

"Obviously we're concerned when armed intruders penetrate defences," said Adam Ereli, a U.S. State Dept. spokesman, adding officials would look at what happened and assess security vulnerabilities.

A spokesman for the Saudi Interior Ministry said the crisis began when militants threw explosives at the gate of the heavily-guarded consulate in the country's second-largest city.

Without elaboration, the statement said security forces then engaged the attackers and "the situation was brought under control."

Bush reacts

Responding to news of the attack, U.S. President George W. Bush told reporters in Washington it is more evidence that "the terrorists are still on the move."

"They want us to leave Saudi Arabia, they want us to leave Iraq, they want us to grow timid and weary in the face of their willingness to kill randomly, kill innocent people. That's why these elections in Iraq are very important," Bush said after an Oval Office meeting with Iraq's interim president, Ghazi al-Yawar.

According to U.S. Embassy spokeswoman Carol Kalin, several non-American personnel had been harmed. There were reports as many as 18 local staff had been trapped inside the building.

As a precaution, Kalin said the U.S. embassy in Riyadh and the consulate in Dhahran have been closed.

U.S. citizens in Saudi Arabia were urged to be very cautious. About 9,000 live in the Jeddah consular area.

Americans and other foreigners have been the objects of such attacks before. Saudi authorities have blamed the al Qaeda terror network for a series of them dating back to 2003.

This attack, however, is the first against a U.S. diplomatic mission in Saudi Arabia, the world's largest oil producer. It is also the biggest assault since May, when at least 22 foreigners and seven security guards were killed in an attack on a housing compound in the eastern city of Khobar.

It comes after what critics say has been an ineffective crackdown on militants by Saudi authorities.

"What they've not been bothering to focus on is obtaining more intelligence as to where other terrorists are operating and simply what happens is the terrorists (who) are killed or captured are merely replaced," said terrorism expert Sajjan Gohel.

Another expert predicted this would be a morale-booster for Saudi militants.

"This was a very hard target to attack, and they pulled it off," Diaa Rashwan, a Cairo-based expert on Muslim militants, told The Associated Press. "For the government, this was a security failure. For the militants, this was a military victory."

With a report from CTV's Alan Fryer and files from The Associated Press