BANI WALID, Libya (AP) — Revolutionary forces are pulling back their fighters from outside a key loyalist stronghold after coming under fierce resistance from supporters of Moammar Gadhafi.

The retreat by anti-Gadhafi forces displayed the firepower and resolve of regime loyalists in turning back the offensive Friday in Bani Walid, about 90 miles (140 kilometers) southeast of Tripoli.

Revolutionary units are now trying to regroup on the outskirts of the town after facing snipers, mortar attacks and rocket barrages as they tried to break into the central part of Bani Walid.

The battle came as other forces tried to push into the heart of Gadhafi’s hometown Sirte on the Mediterranean coast.

THIS IS A BREAKING NEWS UPDATE. Check back soon for further information. AP’s earlier story is below.

SIRTE, Libya (AP) – Libyan revolutionary forces escalated offensives Friday into two key strongholds of Moammar Gadhafi’s rule, battling fierce resistance from snipers and loyalist gunners in Gadhafi’s hometown and a mountain enclave where a pro-regime radio station urged followers to fight to the end.

In Sirte, Gadhafi’s birthplace on the Mediterranean coast, his backers rained gunfire down from mosque minarets and high-rise buildings on fighters pushing into the city from the west, while in the streets the two sides battered each other with high-caliber machine guns, rockets, and rocket-propelled grenades.

In the strategic mountain town of Bani Walid, revolutionary fighters and Gadhafi loyalists traded relentless mortar and rocket fire across a 500-yard-wide desert valley called Wadi Zeitoun that divides the town – and the two sides – between north and south. Fighters dashed through alleyways to set off volleys of fire, hitting a residence that Gadhafi was building on the remains of old fort overlooking the wadi.

“The Gadhafi loyalists have so many weapons. This battle is really crazy,” said Maab Fatel, a 28-year-old fighter, his uniform splattered with bloodstains from carrying a wounded comrade.

Libya’s new rulers appeared to be launching a coordinated assault to break the back of regime holdouts, who still hold a swath of territory along the central coast and into the southern deserts more than three weeks after revolutionary fighters swept into Tripoli and drove out Gadhafi. The whereabouts of the ousted leader and several of his sons remain unknown.

The new leadership has been gaining international support in their campaign to root out the rest of Gadhafi’s regime and establish their authority, with high-profile visits this week by the French president and British prime minister, and on Friday by Turkish Prime Minister Recep Tayyip Erdogan.

Erdogan joined Friday prayers in Tripoli’s Martyrs’ Square, the heart of the city once known as Green Square where Gadhafi’s regime threw rallies of supporters before his fall.

“You have shown the whole world that no one can stand before the power and the will of the people,” Erdogan said in a speech as thousands cheered.

But the resistance in Bani Walid and Sirte underscored how difficult the task of uprooting Gadhafi’s last bastions might be. The revolutionary forces have been looming over the two cities for weeks, and last week they attempted a significant assault on Bani Walid, only to be repelled by unexpectedly strong loyalist counterattacks.

The fighters on Thursday made their first big foray into Sirte – the hub of a loyalist belt across Libya’s central coast – also meeting a heavy backlash. In one particularly bloody sign of how the loyalists are dug in, a bus full of revolutionary fighters hit a roadside bomb in Sirte late Thursday, killing 11, officials said.

On Friday, smoke rose above the city from heavy street fighting, much of it along the main First of September Street running into the city from the west. Loyalists running through the streets fired volleys of RPGs and rockets, and snipers fired down from office towers and minarets, revolutionary fighters at the front said.

The fighters let loose with machine guns fixed on the back of pick-up trucks. Nearby buildings were pockmarked with bulletholes. Commanders said they had captured the city’s old airport on its western edge.

“It’s extra sweet to hit him here,” said one of the fighters’ commanders, Abdul-Salam al-Jayeby. “This is the biggest challenge for Gadhafi because we are going to take his hometown and then we will hunt him down.”

One pickup truck rushed back to the rear lines, its bed bloody and strewn with the body parts of the fighter manning the machine gun, his face mangled. Other fighters shouting “God is great,” pulled his lifeless remains out and comforted his partner, the pick-up driver.

NATO warplanes swept overhead, but is was unclear whether there were fresh airstrikes to help the anti-Gadhafi advance. The alliance said it struck multiple rocket launchers, air missile systems, armored vehicles and a military storage facility in Sirte on Thursday when revolutionary units launched the offensive.

About 150 miles (250 kilometers) to the west in Bani Walid, explosions and gunfire reverberated across the area as revolutionary fighters moving in from the north met the natural barrier of the Wadi Zeitoun valley. Gadhafi fighters were positioned in the valley, which has been irrigated with farms, and were dug in in the neighborhoods on the other side, some on 100-foot-high escarpments overlooking the wadi.

The battle is “hell,” said Jamal Bendalla, a fighter from Tripoli.

Mortars from the loyalist southern side battered buildings on the northern side, where revolutionary fighters rushed back and forth to the front line as ambulances screamed by. Some fighters appeared frustrated by the resistance, arguing with each other.

On the northern side, the fighters raised he new Libyan flag over an abandoned electricity building and a military headquarters in the northern part of Bani Walid. Around the buildings lay a huge Gadhafi poster bent in half and torn billboards with pictures of the ousted dictator. The walls were still sprayed with graffiti reading, “Long live Moammar.”

Inside the town – about 90 miles (140 kilometers) southeast of Tripoli – a radio station believed linked to one of Gadhafi’s main propagandist kept up a steady stream of appeals to fight and rants that demonized the revolutionaries as traitors against the country and Islam.

“Run from Bani Walid and you run straight to your graves,” shouts one man over the radio.

Another portrayed the revolutionaries as trampling Muslim values.

“These revolutionaries are fighting to drink and do drugs all the time and be like the West, dance all night,” the announcer claimed. “We are a traditional tribal society that refuses such things and must fight it.”

Revolutionary forces also claimed success on a third front deep in the southern desert, where they had overtaken the Jalloud Air Force Base on Thursday after defeating Gadhafi loyalists firing rockets and mortars.

Col. Bashir Awidat, who is from the Wadi Shati region, said the fighters also had seized the main towns of Gira and Barak. the two main towns in the area, which is about 70 kilometers north of the pro-Gadhafi city of Sabha.

The unit, which had driven from Tripoli, was sending civilian negotiators to try to persuade villagers in the area – which is about 40 miles (70 kilometers) north of Sabha – to surrender peacefully by replacing Gadhafi’s green flags with the revolutionary tricolor and to take down pictures of the ousted leader.

“The residents have been deceived by the Libyan media. They think that we’ll raid their houses and rob them. The media coverage here has been bad for 42 years and it has trained people to think a certain way and that will take time to change,” he told The Associated Press in an interview at the base.

British warplanes conducted airstrikes Thursday in and around Sabha, including a military vehicle depot used by pro-Gadhafi units.

Maj. Gen. Nick Pope, a British military spokesman, said a dozen missiles were fired on a “large concentration of former regime armored vehicles” that had been located by NATO surveillance.

As battles intensified, Libya’s interim leadership has been pushing forward with efforts to secure international backing.

Erdogan was greeted at the airport by Mustafa Abdul-Jalil, the head of the National Transitional Council, the closest thing Libya has to a government. He traveled to Libya as part of a tour of the Arab world, including Egypt and Tunisia, that is aimed at offering help for the countries and advancing his growing status as a regional leader.

He was expected to discuss how to resume investments in Libya, where Turkish contractors were involved in 214 building projects worth more than $15 billion before the rebellion that ousted Gadhafi.

Turkey initially balked at the idea of military action in Libya, but as a NATO member it is helping to enforce an arms embargo and has led aid efforts. It also hosted a July conference where the U.S. and 30 other nations recognized the NTC as Libya’s legitimate government.