Firm evacuates Saudi workers after five killed
The US embassy urged Americans to leave the kingdom. There was no immediate indication if the latest attack would prompt an exodus among the 35,000 Americans a move that could badly damage the economy of the world's biggest oil exporter.
Saudi Arabia has been battling a year-long insurgency by supporters of Saudi-born Osama bin Laden's al-Qaida network. Saturday's attack suggests militants were determined to act on threats to destabilize the kingdom.