The international criminal court has issued an arrest warrant for Muammar Gaddafi over crimes against humanity committed against opponents of his regime.
The court, based in The Hague, also issued warrants for Gaddafi's son Saif al-Islam and the Libyan intelligence chief, Abdullah al-Senussi -- at the request of the ICC's chief prosecutor.
Gaddafi, in power since 1969, is only the world's second serving head of state to be issued with an arrest warrant. A warrant for the arrest of Sudan's president, Omar al-Bashir, was issued in March 2009 over alleged crimes in Darfur.
Arrests were necessary to prevent a cover-up and more crimes, said the ICC presiding judge, Sanji Mmasenono Monageng.
The investigation launched by the court's chief prosecutor, Luis Moreno-Ocampo, follows a referral on 26 February by the UN security council. Resolution 1970 was supported by all members of the council, including Russia and China, which are unhappy with the Nato bombing campaign.
The ICC has been attacked by some for pursuing legal avenues at the expense of a possible political solution. Critics argue that Gaddafi and his closest associates will have no incentive to relinquish power or go into voluntary exile if they know they are certain to end up in the dock in The Hague.
In Britain, which is playing a leading role in Nato's military campaign, some officials have said privately that the ICC case could be left "on the back burner" in the hope this would encourage Gaddafi to seek sanctuary in a friendly African country.
The Libyan leader has rejected any suggestion that he will stand down or leave the country. Saif al-Islam Gaddafi, who is well connected in the UK, has also vowed to "live or die" in Libya.
The Benghazi-based Libyan rebels have strongly supported the ICC case and submitted evidence to the prosecutor.
Monageng told the court there were "reasonable grounds to believe" the regime had killed or injured and arrested hundreds of civilians and that Muammar Gaddafi exercised full control over the security forces. His son was described as his father's "unspoken successor" and the most influential person in his inner circle, with the powers of a de facto prime minister.
In his submission to the court last month Moreno-Ocampo said Gaddafi had a personal hand in planning and implementing "a policy of widespread and systematic attacks against civilians and demonstrators and dissidents in particular".
"Gaddafi's plan expressly included the use of lethal force against demonstrators and dissidents.
"Methods used to torture alleged dissidents have included tying electric wires around victims' genitals and shocking them with electricity and whipping victims with an electric wire after tying them upside down with a rope connected to a stick."
The Libyan leader ordered snipers to shoot at civilians leaving mosques after evening prayers. His forces carried out a systematic campaign of arrest and detention of alleged dissidents.
The judges of the ICC's pre-trial chamber could have declined the prosecutor's request or asked for further information before issuing the warrants.
The foreign secretary, William Hague, said he welcomed the ICC's decision. "The warrants further demonstrate why Gaddafi has lost all legitimacy and why he should go immediately. His forces continue to attack Libyans without mercy and this must stop."
The ICC was established in 2002 as a permanent court to try those accused of war crimes, crimes against humanity and genocide if the accused's own country cannot or will not do so.