Libyan ruler Muammar Gaddafi remains defiant despite the passage of a UN Security Council measure authorizing the enforcement of a no-fly zone over the country

Libyan ruler Muammar Gaddafi remains defiant despite the passage of a UN Security Council measure authorizing the enforcement of a no-fly zone over the country, vowing a military assault on the eastern city of Benghazi.

Gaddafi announced on the Libyan state radio on Thursday that his forces “will come house by house, room by room" in Benghazi and will “have no mercy and no pity,” Reuters reported.

Pro-regime forces claim to have tightened their grip on Benghazi, the main stronghold of revolutionaries. The regime's heavily armed forces have reportedly reached to within 100 kilometers (60 miles) of the city. Opposition forces, however, have fiercely denied reports that Gaddafi forces are anywhere near the major city.

Human Rights Watch has warned of atrocities and serious violations by Gaddafi forces if they succeed in retaking the city.

The National Libyan Transitional Council, established by the revolutionary forces, has warned of a massacre in Benghazi if the international community does not intervene.

Meanwhile, the United Nations Security Council (UNSC) has adopted a resolution authorizing a limited military intervention in Libya that does not involved ground occupation forces.

French Foreign Minister Alain Juppe has urged an immediate action before it is “too late.” “Everyday, every hour, we see the closing of the clamp on the civilians and the population of Benghazi. We should not arrive too late,” Juppe said.

A military measure led by France, Britain and possibly the United States, could be carried out within hours, French diplomatic sources announced.

Five members of the Arab League, including Jordan, Qatar, Saudi Arabia and the United Arab Emirates, will contribute to the military plan, a report says.

The Arab League officially asked the UNSC to impose a no-fly zone on Libya last week.

Germany, however, has expressed concerns about the consequences of a military action in Libya, saying it will not allow participation of any of its troops in the initiative. “We remain eminently skeptical on the option of military intervention anticipated in this resolution. We see in it considerable risks and dangers,” Foreign Minister Guido Westerwelle said, while insisting that Gaddafi should halt violence against people and quit power.

Ten Security Council members voted in favor of the resolution that authorizes aerial operations and military strikes to impose a no-fly zone over Libya's air space and thus protect the lives of civilians from air attacks by Gaddafi regime,

Brazil, China, Germany, India and Russia abstained from voting on the UNSC resolution, Reuters reported on Friday.