Forces opposing Moammar Gadhafi's remaining loyalists continued their bombardment of the deposed Libyan ruler's stronghold of Sirte, raining rockets and artillery shells into the city Saturday as a sandstorm cloaked the region.

Fighters have battled block by block in Gadhafi’s hometown, 400 kilometres east of Tripoli, since their renewed push into the city on Friday, supported by NATO warplanes.

By late Saturday, anti-Gadhafi forces managed to take control of a central neighbourhood, an area where most of the commanders and officers in Gadhafi's army live, according to Al Jazeera. They said they had succeeded in capturing part of a sprawling conference centre that is believed be the command centre of the former leader's forces.

National Transitional Council revolutionary forces fire their weapons against pro-Gadhafi troops in Sirte, the last major holdout for the former Libyan leader. Ahmad Al-Rubaye/AFP/Getty

Adding to the fierce opposition they are encountering, the anti-Gadhafi forces are now contending with a vicious sandstorm, making visibility low.

The National Transitional Council (NTC) forces are also meeting with heavy sniper fire from Gadhafi loyalists.

Thousands of Sirte's residents have fled since the siege began three weeks ago.

British Defence Secretary Liam Fox vowed to continue NATO airstrikes even after Sirte's fall, saying the international military action would be maintained as long as remnants of the regime posed a risk.

"We have a message for those who are still fighting for Gadhafi that the game is over, you have been rejected by the people of Libya," he told reporters Saturday in Tripoli.

Fox’s comment comes a week after the head of U.S. Africa Command said NATO could end its mission within a week, leaving only drones to do surveillance.

Abdel-Rahman Busin, a military spokesman for the transitional council, said he expected the city to be declared liberated in the next 24 hours.

"They've pretty much taken the city and it's just a few pockets of resistance," he said.

Reports say between 15 to 22 revolutionary fighters have been killed since Friday.

While Gadhafi loyalists still control Bani Walid, in the central mountains, transitional leaders say they will declare liberation once they have Sirte because the city provides them the control they need over all seaports and harbours.

Sirte sits in the centre of the coastal plain where most Libyans live, blocking the busy routes between east and west.

Sirte is strategically located on the coast and divides Libya into east and west. With files from The Associated Press