Libyan military aircraft fired live ammunition at crowds of anti-government protesters in Tripoli, Al-Jazeera television reported Monday.
"What we are witnessing today is unimaginable," said Adel Mohamed Saleh, an activist in the capital whose accounts could not be independently confirmed. "Warplanes and helicopters are indiscriminately bombing one area after another. There are many, many dead.
"Our people are dying. It is the policy of scorched earth," he said.
Another man, identified only as “Victory,” told msnbc.com after touring Tripoli, “We could hear firing every 15 minutes, I don’t know from where really.”
The accounts came as deep cracks opened in Moammar Gadhafi's regime after more than 40 years in power, with diplomats abroad and the justice minister at home resigning, air force pilots defecting and a fire raging at the main government hall after the clashes in the capital Tripoli. Protesters called for another night of defiance in Tripoli's main square despite the government's heavy crackdown.
Arabiya television said the Tripoli clashes Monday left 160 dead.
Human Rights Watch said Monday that at least 233 people had been killed since the protests began last week, but opposition groups put the figure much higher. Most fatalities were in Benghazi, a region where Gadhafi's grip has always been weaker than elsewhere in the oil-producing desert nation.
Gadhafi's son, Seif al-Islam, vowed Sunday that his father and security forces would fight "until the last bullet."
An analyst for London-based consultancy Control Risks said the use of military aircraft on his own people indicated the end was approaching for Gadhafi.
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"These really seem to be last, desperate acts. If you're bombing your own capital, it's really hard to see how you can survive, " said Julien Barnes-Dacey, Control Risks' Middle East analyst.
"But I think Gadhafi is going to put up a fight ... in Libya more than any other country in the region, there is the prospect of serious violence and outright conflict," he said.
Gadhafi's regime appeared to be preparing a new major assault in the capital Monday night. State TV at nightfall announced that the military had "stormed the hideouts of saboteurs" and called on the public to back the security forces as protesters called for a new demonstration in central Green Square and in front of Gadhafi's Tripoli residence.
Snipers had taken position on the roofs of buildings around Tripoli, apparently to stop people from outside the capital from joining the march, according to Mohammed Abdul-Malek, a London-based opposition activist in touch with residents.
Communications into the capital appeared to have been cut, and mobile phones of residents could not be reached from outside the country. State TV showed images of hundreds of Gadhafi supporters rallying in central Green Square Monday evening, waving pictures of the Libyan leader and palm fronds.