Saudi forces are searching today for suspected al-Qaeda militants who killed 22 civilians and took dozens of foreigners hostage in a daring attack on its globally vital oil industry.
Security forces set up nationwide checkpoints after three gunmen, using hostages as human shields, escaped Saudi commandos who stormed a residential compound in the eastern oil city of Khobar yesterday to end a 25-hour siege.
All the hostages who had not been killed were freed.
The kingdom is the world's largest crude oil exporter and state-owned giant Saudi Aramco vowed to keep supplies flowing smoothly in a bid to avert a rise in already-high world oil prices. Most energy markets will not reopen until tomorrow.
The Interior Ministry said 41 people had been held hostage and 201 trapped inside the compound. A Saudi diplomat said nine hostages were killed during the stand-off.
Rescued hostages said none of the civilians had been killed by security forces and one of the staff at the complex said Saudi forces let the gunmen out after they threatened to blow themselves up along with their captives.
An Internet statement purporting to come from al-Qaeda said Osama bin Laden's network had carried out the assault and the hostage-taking, which raised the stakes in the battle Saudi Arabia has waged with the group for a year.
The siege began on Saturday when gunmen in military clothing opened fire on the Al-Khobar Petroleum Centre building, housing offices of major Western oil firms, and stormed into compounds containing oil services offices and employees' homes.
Arab residents had said the gunmen asked them if they were Muslim or Christian before targeting the Christians.
"There were pools of blood, blood is everywhere," said a member of the staff at the upmarket Oasis compound, adding that freed hostages told him there had been more than four attackers.
The hotel where the foreign hostages were held was still sealed off after the siege and security forces were searching for explosives the militants might have left behind.
The Interior Ministry said three gunmen escaped but that Saudi forces wounded and captured their leader. The Khobar assault was the second in less than a month on the Saudi oil industry, and the attacks appear aimed at overthrowing the Saudi monarchy.