Gaddafi defiant as NATO continues to argue over military mission (VIDEO)

As NATO struggled to find consensus over its military strategy, allied air strikes have reportedly been targeting the Libyan capital Tripoli, prompting a defiant appearance by Muammar Gaddafi.

State television broadcast images of the Libyan leader, standing through an open car sun roof — his fist pumping the air — as the sports utility vehicle sped through the streets pursued by supporters.

The impromptu parade came as powerful explosions rocked the city. The BBC quoted sources saying up to 10 students at a university in the city had been injured in the attack.

Gaddafi's forces continued their assault on the rebel-held Misurata, bombarding it with dozens of rockets and killing at least 13 people. Their target was the besieged western city's lifeline port facilities, AP said.

The Libyan leader's daughter made her own defiant appearance on Thursday, telling a crowd of chanting supporters that international demands for her father to leave power were an "insult" to all Libyans.

"In 1911 Italy killed my grandfather in an air strike and now they are trying to kill my father. God damn their hands," Aisha Gaddafi told supporters gathered at her father's compound to mark the 25th anniversary of a U.S. retaliatory bombing raid.

"Leave our skies with your bombs," she said. "We are a people that cannot be defeated."

At a meeting in Berlin on Thursday, NATO foreign ministers put up a united front over their action in Libya, but arguments remained over how much military pressure should be applied on Gaddafi's forces.

The leaders of Britain, France and the United States issued a joint declaration pledging to sustain military operations in Libya. The letter said that Libyans in cities like Misurata and Ajdabiya are enduring "terrible horrors at Gaddafi's hands."

They wrote: "It is unthinkable that someone who has tried to massacre his own people can play a part in their future government.

"The brave citizens of those towns that have held out against forces that have been mercilessly targeting them would face a fearful vengeance if the world accepted such an arrangement. It would be an unconscionable betrayal."

But NATO's supreme allied commander for Europe, U.S. Navy Adm. James G. Stavridid, said that more ground attack aircraft were needed to mount precision strikes on Gaddafi's forces wihout civilian casualties, the LA Times said.