A chronology of violent incidents in Saudi Arabia from the Riyadh bombs of May 2003 onwards:
12 May 2003 - Suicide bombers attack three Riyadh compounds housing foreigners, killing 35 people including at least nine bombers.
14 June 2003 - Security forces raid apartment in Mecca and five suspected Islamic militants die in ensuing battle along with two security agents.
28 July 2003 - Security forces raid farm in al-Qassim and six suspected Islamic militants die in ensuing battle along with two security agents.
23 September 2003 - Security forces raid flats in Jizan and three suspects, including an alleged al-Qaeda operative wanted by the FBI, die in battle along with one security agent.
3 November 2003 - Police clash with suspected al-Qaeda
supporters in Mecca, killing two suspects and uncovering large cache of weapons.
8 November 2003 - Suicide bombing at a Riyadh housing compound
kills 17, most of them Muslims working in Saudi Arabia. US and Saudi officials believe it was masterminded by Abdulaziz Issa Abdul-Mohsin al-Muqrin, suspected of being al-Qaeda's top figure in Saudi Arabia.
29 January 2004 - Five Saudi security agents among six killed in
gun battle which erupts as agents search a suspected militant hideout in Riyadh.
21 April 2004 - Suicide bomber kills five people, including two senior police officers and an 11-year-old girl, in an attack on a government building in Riyadh. An Islamic militant group, the al-Haramain Brigades, claims responsibility.
1 May 2004 - Gunmen attack the offices of Houston-based company ABB Lummus Global Inc in the port of Yanbu, killing six Westerners
and a Saudi. All four are killed in a subsequent shootout.
20 May 2004 - Saudi security forces clash with five suspected
Islamic militants near Buraida, killing four and wounding the fifth.
22 May 2004 - Unidentified gunmen shoot dead a German expatriate on a Riyadh street.
29-30 May - Gunmen attack oil company compounds in Khobar and then take hostages at the Oasis residential building. They escape through a police cordon, prompting accusations of collusion. At least 30 people are killed.
6 June - Gunmen attack a BBC team in Riyadh, killing cameraman Simon Cumbers and seriously wounding correspondent Frank Gardner.
8 and 12 June - Gunmen shoot dead two American citizens in Riyadh in separate incidents.
18 June - Islamist militants behead US citizen Paul Johnson, taken hostage three days earlier. Abdulaziz al-Muqrin is reported to have been arrested shortly afterwards.
3 August - An Irish citizen is shot dead at his Riyadh office.
15 September - Three gunmen kill a Briton in a Riyadh shopping centre. The Saudi wing of al-Qaeda claims responsibility.
26 September - Frenchman, Laurent Barbot, shot dead in Jeddah.
18 October - A top-ranking militant, Abdelmajid bin Mohammad Abdallah al-Manaya, is among three people killed by Saudi security forces in a shoot-out in Riyadh.
17 November - A Saudi policeman dies in a clash with suspected Islamic militants.
6 December - US consulate in Jeddah attacked.