The siege of one of Sirte, Moamer Gaddafi's last bastions, comes as Libya's new rulers said they had unearthed a mass grave in Tripoli of 1,700 prisoners slain by his regime in a 1996 uprising, a massacre that helped trigger the revolt that ousted the despot.
As fighters loyal to the new leadership tightened the vice around Gaddafi loyalists in Sirte, civilians fleeing the city of some 70,000 spoke of rapidly deterioriating conditions for the remaining residents. "The situation in the city is very critical," said Muftah Mohammed, a fish trader who was leaving in a convoy of seven vehicles with around 60 relatives and neighbours. "There is no food, no water, no petrol and no electricity. This has been going on for nearly two months now as Gaddafi forces would not allow us to leave."
Mohammed said that African mercenaries deployed in the city centre and on rooftops had been preventing residents from leaving. "They are from Chad. They used to threaten us if we tried to leave," he said.
"Children are in a particularly bad condition. There is no milk for them. We have all been surviving on just macaroni for several days."
Pro-Gaddafi radio in Sirte kept up a steady barrage of propaganda broadcasts in a bid to rally his remaining loyalists. "You must die for Gaddafi, you must die for country," the radio exhorted, playing a diet of songs extolling the "great guide," the ousted strongman's official title under the old regime.
Another Sirte resident who asked not to be identified was leaving the city with around 20 relatives.
"NATO has been bombing continuously. The children are scared. We had to leave. There was no option," he said.
The alliance said on Monday that its aircraft had hit a command and control node, three ammunition or vehicle storage facilities, a radar facility, a multiple rocket launcher, a military support vehicle and an artillery piece in Sirte.
The previous day, the alliance blew up 29 armed vehicles, a firing position, two command and control nodes and three ammunition storage facilities in the city.
On Monday morning, commanders reported no fighting on the western side on Sirte but on the eastern side an AFP correspondent heard exchanges in late morning after a convoy of some 150 NTC fighters backed by three artillery pieces entered the city.
The front line is now some 10 kilometres (six miles) inside the sprawling coastal city from its eastern gate, Commander Ahmed Zlitni of the NTC operations centre told AFP on Sunday.
There have been repeated reports that one of Gaddafi's sons -- Mutassim -- is holed up in Sirte's southern outskirts. A resident who fled on Sunday told AFP that he had twice seen Mutassim in the past three weeks, once in a command centre set up in a hospital basement.
NTC forces believe that Gaddafi's most prominent son, Seif al-Islam, is in the other major enclave still in the hands of loyalist forces, the desert city of Bani Walid, southeast of Tripoli. "We know exactly where he is," said Commander Omar Mukhtar, whose troops have been laying siege to Bani Walid for several weeks.
The NTC is keen to put Gaddafi and top members of his former regime on trial for what they say were widespread human rights abuses committed during his 42-year rule.
The gruesome find in a mass grave of the remains of prisoners executed at Tripoli's notorious Abu Salim jail was yet further proof of "criminal acts" by Gaddafi's regime, said Khalid Sharif, spokesman for the NTC's military council. "We found the place where all these martyrs were buried," Sharif announced on Sunday in Tripoli.
Salim al-Farjani, a member of the committee set up to identify the remains, appealed for international help. "We call on foreign organisations and the international community to help us in this task of identifying the remains of more than 1,700 people," said Farjani.
The first demonstrations in Libya which finally ousted Gaddafi last month erupted in Benghazi in February, when families of Abu Salim victims called for protests against the arrest of their lawyer. Farjani said he witnessed the gruesome site where the Abu Salim victims were found.
"We were invited to visit the place where the corpses of the prisoners at Abu Salim were found, where we saw scattered human bones," he said.
Farjani also referred to "egregious acts committed against dead bodies, on which acid was poured to eliminate any evidence of this massacre."