Violent clashes escalated late on Sunday in Tripoli's central Green Square between security forces and Libyans demanding an end to the rule of Muammar Gaddafi, their long-serving ruler.
In an address broadcast by state TV in the early hours of Monday, Saif al-Islam Gaddafi, a son of Muammar Gaddafi, said his father would stand firm and warned that Libya could plunge into civil war if the protests did not stop.
He said foreign media, Islamists, even drug addicts were part of a plot to bring down the government and break up the country.
The speech came after demonstrators in Benghazi claimed to be in control of the eastern Libyan city, despite a harsh security crackdown. Human Right Watch said at least 233 people had died, with security forces continuing to use force to end the demonstrations.