Libyan leader Moammar Gaddafi's son warned early Monday that the country faces a bloody civil war if protesters refuse to accept reform offers, in a speech broadcast as gunfire rang out in the capital, saying that his father remained in charge with the army's backing and would "fight until the last man, the last woman, the last bullet."
Saif al-Islam Gaddafi condemned the unprecedented uprising against his father's 41-year rule as a foreign plot, but admitted mistakes were made in a brutal crackdown and urged citizens to build a "new Libya".
"Libya is at a crossroads. If we do not agree today on reforms, we will not be mourning 84 people, but thousands of deaths, and rivers of blood will run through Libya," he said.
Human Rights Watch gave a new death toll on Monday and said at least 233 people have been killed in Libya since the anti-regime protests broke out on Feb. 15 after similar uprisings in Tunisia and Egypt which ended the long rule of two veteran leaders.
U.S. mulling "appropriate actions"
Hundreds of Libyans, some armed with knives and guns, meanwhile, attacked a South Korean-run construction site in Tripoli, sparking a clash in which at least four foreigners were hurt, Seoul's foreign ministry said.
The rioters stormed the site at around 11 p.m. (local time), left and then returned a few hours later, a foreign ministry official told Reuters.
Three South Korean workers were wounded, one of them stabbed, and one or two Bangladeshi workers were hurt, the official said.
Gaddafi's son gave a lower toll than the United States and rights watchdogs who said that hundreds are feared dead in an offensive to crush the uprising carried out by the military, reportedly backed by mercenaries.
A U.S. official said early Monday that the United States was weighing "all appropriate actions" in response to Libya's violent crackdown on protesters and is analyzing the televised address by the son of Libyan leader Gaddafi to see if there are prospects for meaningful reform.
President Barack Obama was being briefing regularly on fast-moving developments in Libya, and his administration will seek "clarification" from senior Libyan officials as it presses for an end to violence against peaceful demonstrators, the official said.
Heavy gunfire broke out in central Tripoli and several city areas Monday for the first time since the anti-regime uprising began, witnesses and an AFP journalist reported.
A witness in the working-class Gurgi area said security forces fired tear gas to disperse protesters.
But confusion prevailed in the city after Gaddafi's speech and unconfirmed rumors that his father had left Libya triggered sounds of celebration, with women ululating and drivers hooting their car horns.
"Libya is not Egypt, it is not Tunisia"
The unrest has spread from the flashpoint city of Benghazi, where demonstrations began on Tuesday, to the Mediterranean town of Misrata, just 200 kilometers (120 miles) from Tripoli.
"This is an opposition movement, a separatist movement which threatens the unity of Libya," Gaddafi said in a fiery but rambling speech which blamed Arab and African elements for fomenting the troubles.
"We will take up arms... we will fight to the last bullet," he said. "We will destroy seditious elements. If everybody is armed, it is civil war, we will kill each other."
"Libya is not Egypt, it is not Tunisia," he said, adding that attempts at another "Facebook revolution" would be resisted.
"Moammar Gaddafi, our leader, is leading the battle in Tripoli, and we are with him."
"The armed forces are with him. Tens of thousands are heading here to be with him. We will fight until the last man, the last woman, the last bullet," he said in a rambling and sometimes confused speech of nearly 40 minutes.
But Saif al-Islam Gaddafi's threats betrayed a note of desperation, and he suggested that the eastern city of Benghazi, Libya's second city, was now out of government control.
"At this moment there are tanks being driven by civilians in Benghazi," he said, insisting the uprising was aimed at installing Islamist rule and that it would be ruthlessly crushed.
And despite the tough talk and finger-wagging, Gaddafi also made some concessions -- pledging a new constitution and new liberal laws with more media freedom.
"If you want us to change the flag and national anthem, we will."
He also admitted "mistakes" on the part of the army in containing the riots, saying they were "not trained to contain riots" and were responding to attacks by "people on drugs."
We will take up arms... we will fight to the last bullet," he said. "We will destroy seditious elements. If everybody is armed, it is civil war, we will kill each other
Saif al-Islam Gaddafi
"Destructive and terrorist" plans
In a performance which veered between threats and concessions, Gaddafi underscored Libya's vast oil wealth and issued a trenchant warning to foreign companies.
"We have one resource that we live on and that is petrol," he said. "All the foreign companies will be forced to leave the country."
Prime Minister Baghdadi Mahmoudi meanwhile told EU ambassadors in Tripoli that there are "very precise plans, destructive and terrorist, that want Libya to become a base for terrorism."
But in a significant crack in the regime's public face, Libya's envoy to the 22-member Arab League announced he was "joining the revolution."
"I have submitted my resignation in protest against the acts of repression and violence against demonstrators and I am joining the ranks of the revolution," Abdel Moneim al-Honi said.
In Benghazi, which has borne the brunt of the violence, protests continued, lawyer Mohammed al-Mughrabi told AFP by telephone.
"Lawyers are demonstrating outside the Northern Benghazi court; there are thousands here. We have called it Tahrir Square Two," he said of the Cairo square central to protests that forced Egyptian president Hosni Mubarak to step down.
Witnesses told AFP by telephone that security forces also clashed with anti-regime protesters in Misrata, saying security forces, backed by "African mercenaries," fired on crowds "without discrimination."
U.N. Secretary-General Ban Ki-moon, meanwhile, called for "the non-use of force and respect for basic freedoms" in North African and Middle Eastern countries wracked by mass uprisings.
"The secretary-general reiterates his call for the non-use of force and respect for basic freedoms," a U.N. spokesman said in a statement, adding that Ban, who had been in contact with regional leaders to discuss the situation, stressed the importance of exercising utmost restraint by all concerned.
The United States and the European Union strongly condemned the use of lethal force in Libya.
Susan Rice, the U.S. ambassador to the United Nations, said the Obama administration was "very concerned" about reports that Libyan security forces had fired on peaceful protesters in the eastern city of Benghazi.
"We've condemned that violence," Rice told "Meet the Press" on NBC. "Our view is that in Libya, as throughout the region, peaceful protests need to be respected."
"We are working to ascertain the facts, but we have received multiple credible reports that hundreds of people have been killed and injured in several days of unrest -- and the full extent of the death toll is unknown due to the lack of access of international media and human rights organizations," U.S. State Department spokesman Philip Crowley said.
EU foreign policy chief Catherine Ashton urged Tripoli to open a dialogue with protesters.
"The EU urges the authorities to exercise restraint and calm and to immediately refrain from further use of violence against peaceful demonstrators," she said during a meeting of EU foreign ministers in Brussels.
"The legitimate aspirations and demands of the people for reform must be addressed through open and meaningful Libyan-led dialogue," Ashton said in a declaration on behalf of the 27-nation bloc.
Western countries have expressed concern at the rising violence against demonstrators in Libya. British Foreign Secretary William Hague said he spoke to Seif al-Islam by phone and told him that the country must embark on "dialogue and implement reforms," the Foreign Office said.
The Internet has been largely shut down, residents can no longer make international calls from land lines and journalists cannot work freely, but eyewitness reports trickling out of the country suggested that protesters were fighting back more forcefully against the Middle East's longest-serving leader.
68-year-old Gaddafi has been trying to bring his country out of isolation, announcing in 2003 that he was abandoning his program for weapons of mass destruction, renouncing terrorism and compensating victims of the 1986 La Belle disco bombing in Berlin and the 1988 bombing of a Pan Am airliner over Lockerbie, Scotland.
Those decisions opened the door for warmer relations with the West and the lifting of U.N. and U.S. sanctions. But Gaddafi continues to face allegations of human rights violations. Gaddafi has his own vast oil wealth and his response to protesters is less constrained by any alliances with the West than Egypt or Bahrain, both important U.S. allies.
Libya has the largest proven oil reserves in Africa with 44 billion barrels as of January 2010, according to the U.S. Energy Information Administration, but it's still a relatively small player compared with other OPEC members.
In January, OPEC said Libya produced 1.57 million barrels of oil per day. That puts it behind Saudi Arabia, Iran, Iraq, the United Arab Emirates, Kuwait, Venezuela, Nigeria and Angola.