TRIPOLI, Libya – Moammar Gadhafi rolled defiantly through the streets of Tripoli, pumping his fists as he poked through the sun roof of an SUV on Thursday – the same day that NATO airstrikes shook the city. The alliance’s foreign ministers, while united in their aim to pressure the Libyan leader to go, argued at a meeting over whether to step up military operations that have so far failed to rout him.

Gadhafi gave no sign that he’s willing to relent, despite two months of civil war and mounting international pressure for him to move aside. Instead, his loyalists pounded rebel positions in the besieged western city of Misrata with dozens of rockets for several hours, killing at least 13.

The main target of the assault was Misrata’s port, the only lifeline for rebels who have been trying to defend positions in the city, Libya’s third-largest, against Gadhafi’s forces.

Early Friday, Gadhafi’s daughter Aisha sent another defiant message from her father’s Bab al-Aziziyah compound in the capital of Tripoli, badly damaged exactly 25 years ago, in an April 15, 1986 bombing by U.S. warplanes. That attack came in response to a bombing that had killed two U.S. servicemen at a German disco.

“Leave our skies with your bombs,” Gadhafi’s daughter told a cheering crowd, addressing the international community. “We are a people that cannot be defeated.”

Wearing a green headscarf and a leather jacket, she waved to the crowd of several hundred and led them in chants from a second-floor balcony that in the past was used by her father to deliver speeches.

On Thursday, several large explosions were heard in Tripoli and black smoke rose from the southeastern part of the city, followed by the sound of anti-aircraft guns, a resident said.

Libyan state television showed Gadhafi — dressed in a black Western blazer, black crew neck T-shirt, sunglasses and a hat — standing through the open sun roof of a sport utility vehicle on a fist-pumping, rapid ride through Tripoli with dozens of supporters chasing behind him. Libyan TV said the trip came on the same day that NATO airstrikes hit military and civilian areas in the capital.

The unconfirmed TV report said there were civilian casualties from the attacks. The fighting in Libya began in mid-February when large anti-government protests escalated into a civil war. Rebels hold much of eastern Libya, while Gadhafi controls the west, with the front line shifting back and forth in the middle. Three weeks of international airstrikes haven’t routed Gadhafi’s forces.

Gadhafi’s troops unleashed three hours of heavy shelling on the port city of Misrata, which is partly held by rebels. The port is Misrata’s only lifeline, and government forces fired tank shells and dozens of Grad missiles, according to witnesses who spoke on condition of anonymity because they feared retaliation.

“They want to flatten the area to deploy the troops on foot and invade the city,” said one of the witnesses, a doctor whose first name was Ayman. He added that a ship sent by Doctors Without Borders to evacuate 165 critically injured people to Tunisia had been scheduled to arrive Thursday morning at Misrata’s port, and he believed the government had shelled the port to interfere with the humanitarian aid.

Gadhafi forces control a highway on the outskirts of Misrata, Libya’s third-largest city.

U.N. Secretary-General Ban Ki-moon chaired a Cairo meeting of regional and international organizations on Libya and set three targets: reaching and implementing a cease-fire, delivering humanitarian aid and starting a dialogue on Libya’s future.