Libyan state television reported Sunday night that international airstrikes were targeting Moammar Gaddafi’s hometown and stronghold of Sirte for the first time.

Foreign journalists in the city reported loud explosions and warplanes flying overheard. And an Associated Press reporter in the capital said international forces were also heavily bombarding the city that is Gaddafi’s main support base. There were at least nine loud explosions in Tripoli after nightfall and anti-aircraft fire was heard.

“Civilian and military areas in Tripoli were hit a short while ago by the crusader, colonialist aggressors,” Libyan state television said in a written news flash.

The explosions were followed by sustained bursts of anti-aircraft gunfire by Libyan forces.

Meanwhile, according to AP, residents in the contested city of Misrata in western Libya reported fighting Sunday between anti-government rebels and pro-Gaddafi forces firing from tanks on residential areas. And Reuters news services reported that witnesses in Sirte, Gaddafi’s hometown, and in the capital Tripoli said they had heard at least 10 explosions Sunday night.

A Reuters reporter in Sirte, midway between rebel-held Benghazi and Tripoli, said it was not clear if the four explosions there had been in the town or on its outskirts.

The reporter, part of a group of Western media taken to Sirte by the government, had earlier said a convoy of 20 military vehicles including truck-mounted anti-aircraft guns had been seen leaving Sirte and moving westwards toward Tripoli, the news service reported.

Libyan rebels, emboldened by the capture of Ajdabiyah to the east of Sirte, were pushing west Sunday to retake more territory from Gaddafi’s forces, which were pulling back under pressure from Western air strikes, Reuters said.

Earlier Sunday, a day after retaking the town of Brega, rebels in Libya said they taken the oil port of Ras Lanuf.

“They are just clearing the city,” said Iman Bougaighis, a spokeswoman for the opposition. “After that they plan to stay there, overnight or longer.”

The rebels’ advance westward has gained momentum since Friday, when coalition bombings allowed them to subdue Gaddafi forces that had been positioned in the strategic town of Ajdabiya for a week.

While Brega and Ras Lanuf are sparsely populated and were expected to be easy to retake, the next town, Bin Jawwad, 27 miles to the west, was the point at which Gaddafi’s forces repelled the rebels’ westward advance earlier this month.  

After Bin Jawwad, the next town along the coast is Gaddafi’s hometown of Sirte, where a rebel victory would have immense symbolic significance.

In rebel-held Misurata, 131 miles from Tripoli, which is surrounded by Gaddafi forces, rebels are running low on ammunition and Gaddafi forces brought in additional snipers overnight, Bougaighis said, adding that a ship carrying humanitarian aid was able to reach the city Sunday.

She was unable to confirm reports that rebels had captured one of Gaddafi’s most senior soldiers, General Bilgasim Al-Ganga, in the Ajdabiya battle.

Days of coalition airstrikes appeared Saturday to have pushed open the door to western Libya for anti-government rebel forces, which retook the strategic city of Ajdabiya as a weakened military loyal to Gaddafi fell back.

Although fluid and potentially reversible, the rebel gains on the ground were the clearest indication yet that intensive airstrikes carried out by U.S., French and British warplanes and naval assets over the past week have softened up Libya’s military considerably.

The rebel advance also underscored the central role that international forces are playing in Libya’s internal conflict, providing military support to rebels that Libyan officials condemned for exceeding the United Nations mandate to protect civilians.

Addressing the nation Saturday, President Obama said, “We’re succeeding in our mission.”

“This is how the international community should work: more nations, not just the United States, bearing the responsibility and cost of upholding peace and security,” Obama said in his weekly radio and Internet address.

Obama has been criticized by some for failing to clearly define U.S. interests in Libya’s war and for leaving ambiguous what he sees as the American endgame in the oil-rich North African nation.

Initially reluctant to open a third military front in a Muslim country, Obama eventually pushed for a broad U.N. resolution after days of watching Gaddafi’s forces advance on Benghazi, the rebels’ provisional capital. Gaddafi had warned Libyan civilians in the rebel-held east that he would show “no mercy” unless they surrendered, and Obama feared a mass killing if the ragtag insurgency collapsed.

The U.N. resolution authorizing military action in Libya limits operations to those necessary to protect civilians, potentially leaving Obama’s long-term policy goal of removing Gaddafi unmet by the airstrikes and no-fly zone. He has ruled out sending U.S. troops to Libya.

But the rebel counteroffensive Saturday revealed vividly the debilitating effect that days of bombing and missile strikes have had on Gaddafi’s forces, now giving back territory they had taken before Operation Odyssey Dawn began seven days ago.

Al-Jazeera English showed footage of rebels dancing on tanks and celebrating after the soldiers pulled out of Ajdabiya, which sits 530 miles east of Tripoli, Libya’s capital, along a strategic east-west highway that runs through desert and along the coast.

Reuters news service reported that the bodies of more than a dozen of Gaddafi’s soldiers lay strewn around the town’s western entrance, where the fighting was fiercest. A truckload of ammunition was abandoned, and shell casings lay scattered on the ground.

But the rebels remain a long way from being in a position to approach Tripoli.

To reach the capital, they will have to traverse hundreds of miles of sparsely populated desert highway that runs through some staunchly loyalist areas, notably heavily guarded Sirte. On their last push west they reached Bin Jawwad, 37 miles beyond Ras Lanuf, before they were forced back by government soldiers. Bin Jawwad is more than 300 miles east of Tripoli.

In Tripoli, deputy foreign minister Khaled Kaim confirmed that Libyan forces had retreated from Ajdabiya and called for an urgent meeting of the U.N. Security Council to address Libyan complaints that the air assault by U.S., British and French warplanes exceeds the U.N.-approved mission.

“Their direct role in the fighting has become clear,” he said. “It’s outside the mandate. What they are trying to do is push the country to civil war.”

Defense Secretary Robert Gates said in an interview taped Saturday for CBS’s “Face the Nation” that there is no proof of the Gaddafi government claims that coalition airstrikes have killed civilians, the Associated Press reported.

According to AP, Gates said that intelligence reports indicate Gaddafi supporters are putting bodies of people killed by government forces at sites attacked by coalition planes.

Even as the government forces retreated from Ajdabiya, they launched a renewed push to seize the rebel-held city of Misurata in western Libya, which has been besieged by government forces for the past month.

Residents and rebel spokesmen in the city said busloads of gunmen had arrived from the direction of Tripoli on the western edge of the city in the afternoon, and began going house to house, forcing residents to flee their homes at gunpoint.

A spokesman for the self-appointed rebel city council said there were nine buses in all, carrying about 1,000 gunmen, who occupied a school in the area and then began terrorizing residents.

His mother-in-law was told to leave her home without packing any belongings and walked two miles into the center of the city to find refuge with relatives, he said.

Gaddafi’s forces also sustained their random bombardment of city neighborhoods, according to Mohammed, another rebel spokesman contacted over the Internet.

Coalition airstrikes against Gaddafi positions on the outskirts of Misurata have forced the Libyan army to move deeper into the center of the city, where they are protected by the vicinity of civilians, he said.

“Maybe the coalition attacks have helped us in some way, but they have forced all the army of Gaddafi to enter inside the city and now they have no choice but to stay in the city and die,” he said. The loyalist forces have taken control of the main road running through the city and have set up mortar positions in high buildings, he said.

Wilson reported from Washington. Correspondent Tara Bahrampour in Benghazi contributed to this report.