Seven suspects were reported dead and an eighth was critically wounded. "Security forces are continuing mop-up [operations] at the site," an interior ministry statement said. ...

A security source quoted by al-Jazeera television said they belonged to a "deviant group" - the term used by Saudi officials to describe supporters of al-Qaida. ...

A local hospital said it had treated 51 security personnel for injuries by midday yesterday.

That illusion was very publicly shattered in May 2003 when militants launched multiple gun and bomb attacks on housing compounds in Riyadh. At least 29 people died, including nine attackers.

Since then, although vast quantities of arms have been seized, hundreds of suspects rounded up and 21 of the 26 men on the kingdom's most-wanted list arrested or killed, attacks have continued.

Among the latest was an attempt to storm the US consulate in Jeddah last December which left five staff and three attackers dead. Later in the same month car bombs targeted the interior ministry and a special forces training centre in Riyadh.