Reports from Libya indicate thousands may have been killed or injured as the government crackdown escalates "alarmingly", UN human rights head Navi Pillay has said. For the past week, fighting has raged between anti-government forces and troops loyal to Libyan leader Col Muammar Gaddafi, in power for 42 years.
Witnesses in Tripoli say pro-Gaddafi forces have opened fire on protesters. Nato ambassadors are holding emergency talks. Around the capital, Tripoli, an elite brigade commanded by Col Gaddafi's son Khamis is believed to be dug in.
The UK and France are pushing for an arms embargo and a war crimes investigation. "The violence we have seen is appalling and unacceptable," said Prime Minister David Cameron. "People working for this regime... should remember that international justice has a long reach and a long memory."