SIRTE (Reuters/AFP) - Libyan provisional government forces backed by NATO warplanes raced through the eastern outskirts of Sirte on Monday, closing in on Muammar Gaddafi loyalists holed up in one of the last two bastions of the deposed leader. Thick, black smoke billowed into the air as National Transitional Council (NTC) fighters battled loyalist troops at a roundabout about 2 km (1.2 mile) from the center of Gaddafi's home town, Reuters journalists said. The thud of large explosions could be heard as NATO aircraft roared overhead. NTC fighters said the jets were striking the positions of Gaddafi loyalists. The advance came two days after anti-Gaddafi fighters west of Sirte drove to within a few hundred meters of its center before pulling back on Sunday to make way for NATO strikes. On the western edges of Sirte on Monday, NTC fighters and Gaddafi loyalists traded heavy machine gun fire, rocket-propelled grenades and artillery rounds. Snipers loyal to Gaddafi could be seen on building rooftops. NATO aircraft flew overhead. NATO would not comment on its operations in Sirte on Monday. It said its planes hit eight targets on Sunday, including ammunition stores and rocket launchers. Interim government forces have previously retreated from Sirte and the other remaining Gaddafi stronghold, Bani Walid, after poorly organized attacks met fierce resistance from loyalists. Sirte lies between Tripoli and the eastern city of Benghazi, both now held by the NTC whose rebel fighters overran the capital five weeks ago after six months of fighting. Taking Sirte would be a huge boost for the NTC, which is trying to establish credibility as a government able to unite Libya's fractious tribes and regions, and a blow for Gaddafi, widely believed to be in hiding somewhere in Libya. Humanitarian organizations have raised the alarm over conditions for civilians cut off in Sirte and in Bani Walid to the south. "God willing we can enter Sirte by tonight," NTC fighter, Emad al-Amamy, told Reuters on the eastern edge of the city earlier on Monday. Scores of civilians in cars laden down with personal belongings continued to stream out of the town to both the east and west. NTC fighters checked them, looking for wanted figures among those who were, and may still be, loyal to Gaddafi. International aid groups are demanding access. Meanwhile, Britain said Monday it has agreed with NATO to withdraw the five Apache helicopters that it has in service over Libya, in a major sign that the alliance's air mission is winding down. Britain deployed the army attack helicopters in June to support forces fighting then-leader Moamer Kadhafi. The choppers were based on the Royal Navy carrier HMS Ocean which has been based in the Mediterranean Sea. Meanwhile, the UN Humanitarian Coordinator for Libya Panos Moumtzis said on Monday that the United Nations is expected to end its emergency humanitarian operations in Libya at the end of November. Humanitarian operations are "for the time being expected for the next eight weeks until the end of November," he told reporters. "We hope the country will be in a new phase" by then, Moumtzis said, explaining that at that point Libya would be in need of "technical" assistance, to develop the country and bring about electoral and judicial reforms.