SIRTE, Libya — Families in pickup trucks stacked with mattresses and jugs of water fled Moammar Gadhafi's hometown of Sirte Tuesday ahead of an expected new push by revolutionary forces to seize the city from die-hard loyalists of the fugitive leader.

Fleeing residents said they had been living under a state of siege with Gadhafi's forces preventing them from leaving, while living conditions deteriorated and the city came under constant rocket fire and NATO bombardment.

"I tried to leave earlier with my family, but Gadhafi's forces wouldn't let me," said Abdullah Mohammed, a 34-year-old computer engineer traveling with his wife, two daughters and son. "We managed to run away at dawn by taking back roads out of the city."

Youssef Ramadan, 35, said there has been no power since Aug. 20, a day before revolutionary forces swept into the capital Tripoli and forced Gadhafi into hiding.

"There's no fuel and food is running low," he said. "A lot of civilians are stuck in their houses because of the fighting." Ramadan, who was taking his wife, 2-year-old daughter, 7-year-old son, brother and mother out of the city of about 100,000 people, said regime forces were using houses, schools and hospitals to store ammunition.

Tripoli fell to Gadhafi opponents in late August after a six-month civil war with NATO airstrikes aiding the rebels — marking the collapse of Gadhafi's nearly 42-year rule. While Libya's new leaders have control over much of the country, they have been unable to rout Gadhafi's loyalists from Sirte and two other major strongholds, the mountain enclave of Bani Walid and Sabha, deep in the southern desert.

Anti-Gadhafi forces said Monday they had captured the airport and other areas but still faced pockets of resistance.

The ousted Libyan leader tried to rally supporters from hiding on Tuesday, saying in an audio recording that his regime is still alive.

"What is happening in Libya is a charade gaining its legitimacy through airstrikes that will not last forever," he said in the statement broadcast on the Syrian-based Al-Rai TV, which has become his mouthpiece. "It's hard to bring down this regime because it represents millions of Libyans."

NATO has launched over 8,700 strike sorties on Libya since late March, with the latest attacks Monday focusing on armed vehicles and rocket systems in Sirte as well as air missile systems and facilities in Sabha, NATO said in a statement. The Western military alliance said it also struck a command control node in Bani Walid.

The transitional Libyan government has insisted it will press forward with efforts to rebuild the government despite the continued fighting. But Gadhafi's continued defiance has raised fears the country could face a protracted insurgency such as those in Iraq and Afghanistan.

President Barack Obama is about to announce that the U.S. is sending its ambassador back to Tripoli to head a reopened U.S. embassy there, according to prepared remarks released ahead of Obama's speech at a United Nations meeting on Libya Tuesday. The president urges remaining regime loyalists to join the new Libya and vows to stand with Libyans as they reshape their country.

Revolutionary fighters tried to push into Sirte, 250 miles (400 kilometers) southeast of Tripoli on the Mediterranean coast, over the weekend but were driven back by fierce rocket and gunfire. They pulled back to regroup, although the two sides exchange fire daily.

About 30 families were lined up to get fuel from a tanker parked about 12 miles outside Sirte with pickup trucks and cars packed with mattresses, water, crates of onions and suitcases in the back.

Abdul-Salam el-Ebadi, 44-year-old math teacher who lives on the outskirts of Sirte, said the anti-Gadhafi forces were encouraging them to leave because they're in the range of weapons from both sides.

"We hear a lot of fighting, but we don't know where it is because we have to hide in our houses," he said. He was leaving with his elderly father in the passenger seat as part of a 10-car convoy of 50 to 60 people.

Revolutionary forces on the western outskirts of the city said they were encouraging residents to leave so they could move in with heavy weapons coming in from Misrata.

"Our guys are going inside the city to give the families what they need, water and fuel so they can leave," field commander Mohammed Mebeggan said as NATO warplanes flew overhead. "We are giving them the opportunity to leave. Today is the last day."

Hesham Samedi, a doctor at a field hospital in a mosque on Sirte's western outskirts, said four people were killed and seven wounded on Tuesday, most hit by shrapnel.

Fighters in Misrata said their plans to root out pro-regime forces in Sirte was focused Tuesday on cutting off military weapons to Gadhafi loyalists coming from the south. The Misrata Military Council said they secured a road to Weddan, about 280 kilometers (175 miles) south of Sirte.

In Bani Walid, revolutionary commanders tried to reorganize their forces after three days of chaotic fighting, with frustration high over weeks of standoff. Official forces withdrew to regroup after a fierce battle, and untrained volunteers have been launching sporadic assaults and drawing retaliatory fire from Gadhafi's forces.

Eight military leaders met with volunteer representatives on Monday evening and field commander Younis al-Toumi said the young men had agreed to follow the national army's commands.

"The national army is back at the checkpoints and we are only allowing those who have registered with us to pass into the front line," al-Toumi told The Associated Press.

Lack of discipline has been a common problem since largely ragtag groups of anti-Gadhafi activists first took up arms after the uprising started in mid-February and evolved into a civil war.

On Tuesday at a feed factory being used as a checkpoint outside Bani Walid, men passed a list around to take down the names and information of the volunteers in a bid to organize them into official brigades. One army official shouted at volunteers to stop randomly shooting for target practice and ordered them to introduce themselves to fighters from the national army.

"These young boys have more than the necessary enthusiasm, but after seeing that many of them are dying needlessly they realize it is the time to organize," said al-Toumi.

Associated Press writers Hadeel al-Shalchi in Wadi Dinar and Aya Batrawy in Cairo contributed to this report.