Libyan leader Muammar Gaddafi's four-decade-old rule appeared in increasing jeopardy on Monday as anti-government protests reached the capital for the first time, leaving dozens dead at the hands of security forces and several towns in the east under opposition control.
And in a statement that threatened to further escalate the crisis, one of Gaddafi's sons said the veteran leader would fight the popular revolt till "the last man standing".
Just 10 days after a people's revolt overthrew the seemingly impregnable 30-year-old rule of Hosni Mubarak in Egypt, analysts said Libya was heading for civil war.
Protesters said they'd taken control of at nine towns in the east, including Benghazi, which has most of Libya's oil fields.
There were other signs that Gaddafi's iron grip was being severely tested: army units defected to the opposition, a coalition of clerics told Muslims it was their duty to rebel against the leadership because of their "bloody crimes against humanity", and the justice minister as well as the country's ambassador to India resigned to protest the "excessive use of violence" against protesters.
There were reports that soldiers who refused to fire on civilians were executed by Gaddafi's officers in Benghazi.
The revolt has left more than 200 people dead so far. Al Jazeera quoted medical sources as saying the latest protests in Tripoli alone claimed 61 lives.
Making an appearance on national TV, Saif al-Islam Gaddafi said late on Sunday the army would enforce security at any price.
"We will keep fighting till the last man standing, even to the last woman standing."