Source changed, details added (first version was published at 02:42)
Muammar Gaddafi may have left his country for Venezuela, Libyan ambassador to China told Qatari Al-Jazeera TV channel.
Hussein Sadiq al Musrati has resigned on air with Al Jazeera Arabic. He called on the army to intervene, and has called all diplomatic staff to resign.
He made claims about a gunfight between Gaddafi's sons and also claimed that Gaddafi may have left Libya.
Al Jazeera has no confirmation of these claims.
Demonstrations against the regime of Gaddafi began on Tuesday evening in Benghazi, Libya's second largest city after the capital Tripoli.
The northern coastal city of Misurata, and Al Bayda town, were also the scene of demonstrations.
Emboldened by the successful revolutions in Tunisia and Egypt, thousands of Libyans have been calling for the ouster of Gaddafi, who has been in power for 41 years.
Dozens of people were arrested in Libya over the past few days, the official news agency reported late on Saturday. They are accused of belonging to a "foreign network" and seeking to destabilize the country and the people's national unity.
The group included Tunisian, Egyptian, Sudanese, Turkish, Palestinian and Syrian citizens, the agency quoted sources close to the investigation as saying.