International condemnation is growing in response to reports that Libyan leader Muammar Gaddafi is using tanks, helicopters and fighter jets to quell the most serious challenge to his 42-year rule.
Nearly 300 people are reported to have been killed in violence in the capital, Tripoli, and across the country as demonstrations entered their second week .
Joining a lengthening list of high-level desertions, Abdul-Fatah Younis, the interior minister and an army general, announced his renunciation of his post and support for the "February 17 revolution".
In a video aired by Al Jazeera on Tuesday, he was seen sitting on a his desk and reading a statement that urged the Libyan army to "join the people and respond to their legitimate demands".
Just hours earlier, Gaddafi vowed to fight on and die a "martyr" in a 75-minute-long speech broadcast on the north African nation's state TV.
"I am not a president to step down ... This is my country. Muammar is not a president to leave his post," he said.
"I have not yet ordered the use of force, not yet ordered one bullet to be fired ... when I do, everything will burn."
He called on supporters to take to the streets to attack protesters. "Leave your homes and attack them in their lairs ... Starting tomorrow the cordons will be lifted, go out and fight them."
Just minutes after his speech, Al Jazeera's correspondent in Cairo reported that Amr Moussa, the Arab League chief, had decided to discontinue the participation of the Libya delegation in the meetings of the council and all its institutions.
With concern mounting over the crisis in Libya, the Security Council in New York held an emergency meeting late on Tuesday and issued a press statement strongly condeming the violence against civilians.
"The members of the Security Council expressed grave concern at the situation in Libya. They condemned the violence and use of force against civilians, deplored the repression against peaceful demonstrators, and expressed deep regret at the deaths of hundreds of civilians."
Al Jazeera's Scott Heidler, reporting from the UN in New York, said that the international community is demanding something stronger from the Security Council.
"They would like to see a resolution that calls for action but that is going to take a lot longer to process. The Security Council wanted to issue this press statement first and then see if they could do more to prevent bloodshed in Libya."
Navi Pillay, the UN human rights chief, has called for the "immediate cessation of grave human rights violations committed by Libyan authorities". Citing reports of the use of machine guns, snipers and combat jets against civilian protesters, she also called for an independent, international investigation into the killings that have wracked the country for days.
"The callousness with which Libyan authorities and their hired guns are reportedly shooting live rounds of ammunition at peaceful protesters is unconscionable," she said.
Mona Rishmawi, a legal adviser to the UN High Commissioner on Human Rights, told Al Jazeera they were extremely concerned by allegations of the use of "hired guns" against civillian protesters in Libya. She said intergovernmental bodies must show a united front and send a clear message that what is going on in Libya must stop right now.
Latin American allies
The bloody upheaval in Libya is creating an uncomfortable challenge for Gaddafi's leftist Latin American allies, with some keeping their distance and others rushing to his defence.
Peru suspended diplomatic ties with Libya on Tuesday, becoming the first nation to take such a measure, however; Fidel Castro, the former Cuban president, said that the unrest may be a pretext for a NATO invasion of Libya.
Daniel Ortega, the Nicaraguan president, also offered support for Gaddafi, saying he had telephoned to express solidarity.
Venezuela's Hugo Chavez, on the other hand, has stayed mute. Bolivia came closest to criticising the government in Tripoli, issuing a statement expressing concern over "the regrettable loss of many lives" and urging both sides to find a peaceful solution.
Ali al-Essawi, who resigned as Libyan ambassador to India, told Al Jazeera on Tuesday that fighter jets had been used by the government to bomb civilians.
He said live fire was being used against protesters, and that foreigners had been hired to fight on behalf of the government. He called the violence "a massacre", and urged the UN to block Libyan airspace in order to "protect the people".
Earlier, Ibrahim Dabbashi, Libya's deputy ambassador to the United Nations, accused Gaddafi of launching a "genocide against the Libyan people".
The Libyan ambassador to India Ali al-Essawi tells Al Jazeera why he resigned from his post
Meanwhile, the UN refugee agency, UNHCR, urged Libya's neighbours not to turn back those fleeing the violence, as hundreds of refugees streamed into Egypt on tractors and lorries, describing a wave of killing and banditry unleashed by the revolt.
Libyan guards have withdrawn from their side of the border and Egypt's new military rulers - who took power following the overthrow of Hosni Mubarak - said the main crossing would be kept open round the clock to allow the sick and wounded to enter.
Libya's state broadcaster quoted Saif al-Islam Gaddafi, the son of Muammar Gaddafi and widely seen as his political heir, as saying that armed forces had "bombarded arms depots situated far from populated areas". He denied that air raids had taken place in Tripoli and Benghazi.
The government says that it is battling "dens of terrorists".
State television on Tuesday dismissed allegations that security forces were killing protesters as "lies and rumours".
Benghazi, Libya's second city, which had been the focal point of violence in recent days, has now been taken over by anti-government protesters, after military units renounced their posts and joined the demonstrators.
According to the Paris-based International Federation for Human Rights, protesters are also in control of Sirte, Tobruk in the east, as well as Misurata, Khoms, Tarhounah, Zenten, Zawiya and Zouara.
Washington and Europe have demanded an end to the violence and Guido Westerwelle, Germany's foreign minister, said: "A ruling family, threatening its people with civil war, has reached the end of the line."