Forces loyal to Libya's new rulers surged into the desert town of Bani Walid Friday in a fierce attack on one of the last strongholds still in the hands of Moammar Gadhafi loyalists that could prove a major turning point in the war.

Explosions and gunfire echoed over the hills surrounding the town, which has been under siege for two weeks, with hundreds of die-hard supporters of the country's fugitive former ruler concentrated around its center.

There was also a report, on Al-Jazeera television, of fierce fighting at Gadhafi's home town of Sirte on the coast, a day after interim government forces announced a breakthrough.

Turkey's prime minister was expected in Tripoli, a day after the French and British leaders won a hero's welcome there for helping to overthrow Gaddafi. Turkish TV said Recep Tayyip Erdogan had arrived in mid-morning.

Erdogan, on a North African tour to assert Ankara's regional influence, will be hoping to reap political and economic dividends from Libya's new rulers for his country's help in their struggle to end Gadhafi's 42-year grip on power.

After nearly seven months of fighting, anti-Gadhafi forces backed by NATO air power control most of Libya, including oil-producing centers and the capital, which they seized last month.

But they have met fierce resistance in a handful of pro-Gadhafi bastions such as the desert town of Bani Walid, the southern outpost of Sabha and Sirte, Gadhafi's birthplace 450 km (280 miles) east of Tripoli.

On Friday, truckloads of anti-Gadhafi troops shouting Let's go! Bani Walid! and columns of pickup trucks mounted with anti-aircraft guns hurtled toward the town, 180 km (110 miles) south of Tripoli, kicking up clouds of dust in the desert.

We are going in. We finally have the orders. God is greatest. God willing, Bani Walid will be free today, fighter Mohammed Ahmed said, his rifle sticking out of his car window.

A short time later, the sound of heavy fighting could be heard from within the town.

Fighters loyal to the National Transitional Council were also said to have moved into Sirte on Thursday.

They have now entered the city. There was a coordinated push from the south, east and west and from along the coast. I'm not sure how far they have been able to enter, Abdulrahman Busin, a military spokesman for the NTC, said on Thursday.

They are coming under heavy fire. There is a particular problem with snipers.

Gadhafi's spokesman said he had thousands of supporters.

We are telling you that as of tomorrow there will be atrocious attacks by NATO and their agents on the ground on the resisting towns of Sirte, Bani Walid and Sabha, Moussa Ibrahim told Syrian-based Arrai television late on Thursday.

The television said 16 people had been killed in Sirte, including women and children, as a result of NATO bombing, and that Gaddafi forces had destroyed a NATO warship and several vehicles. None of the reports could be independently verified.

TURKEY'S ROLE

France and Britain spearheaded the air campaign that ousted Gadhafi, but Turkey -- which had contracts worth $15 billion in Libya -- backed it reluctantly and was slow to recognize those now leading the oil-rich north African state.

French President Nicolas Sarkozy and British Prime Minister David Cameron were told their support may be repaid in business contracts with the oil-rich North African state.

A Turkish ship did play a key role in evacuating civilians from the coastal town of Misrata while it was besieged by Gadhafi forces, and Ankara has recently been vocal in supporting the NTC and provided it with $300 million in cash, loans and other aid.

Turkish companies with business in Libya are hoping the council will honor pending payments once assets are unfrozen, and Energy Minister Taner Yildiz has said he wants state-owned oil and gas exploration company TPAO to resume oil exploration and production work in Libya if security is established.

That depends to a large extent on the fate of Gadhafi who, wanted by the International Criminal Court, is rumored to be hiding in one of the loyalist strongholds.

In Benghazi, seat of the uprising which early intervention by French and British jets helped to save from Gadhafi's army in March, Sarkozy and Cameron were treated to a rowdy welcome on Thursday, shouting over a cheering crowd.

It's great to be here in free Benghazi and in free Libya, said Cameron as he strained to be heard above the chants in scenes from the former rebel stronghold televised live across the globe.

The French president, struggling for re-election next year, beamed at grateful chants of One, two, three; Merci Sarkozy! while the two leaders, flanking NTC chairman Mustafa Abdel Jalil, held his arms aloft like a victorious boxer.

Although Sarkozy denied talk among Arabs of under the table deals for Libya's riches, Jalil said key allies could expect preferential treatment in return for their help in ending Gadhafi's rule.

Erdogan, who has visited Egypt and Tunisia this week, has been holding up Turkey's blend of Islam and democracy as a model for the movements that have toppled longtime Arab rulers in Tunis, Cairo and Tripoli.

He has already won plaudits from Libya's new rulers.

We expect the world community to follow the wonderful support of Turkey, its leading role and effort. Turkey has done an amazing job, Aref al-Nayed, a leading figure in the NTC, told a recent international summit on Libya in Istanbul.

(Reporting by Maria Golovnina near Bani Walid, Libya, William MacLean, Alexander Dziadosz and Joseph Logan in Tripoli, Sherine El Madany in Ras Lanuf, Emma Farge in Benghazi and Barry Malone and Sylvia Westall in Tunis; Writing by Philippa Fletcher; Editing by Giles Elgood and Alastair Macdonald)