Leaders of Britain, France and the United States have vowed to continue their military campaign in Libya until Muammar Gaddafi leaves power.
In a strongly worded, jointly written article published in newspapers on both sides of the Atlantic, British prime minister David Cameron, French president Nicolas Sarkozy and US president Barack Obama said leaving Gaddafi in power would be an "unconscionable betrayal" of the Libyan people.
"It is unthinkable that someone who has tried to massacre his own people can play a part in their future government," the leaders wrote in an opinion piece released on Thursday.
"So long as Gaddafi is in power, NATO and its coalition partners must maintain their operations so that civilians remain protected and the pressure on the regime builds," they said.
"Then a genuine transition from dictatorship to an inclusive constitutional process can really begin, led by a new generation of leaders. For that transition to succeed, Colonel Gaddafi must go, and go for good."
The reaction from the Gaddafi camp was swift as the Libyan leader's daughter Aisha told a rally in Tripoli, at a family compound bombed by the Americans in 1986, that demanding her father's departure was an insult to the Libyan people.
"Talk about Gaddafi stepping down is an insult to all Libyans because Gaddafi is not in Libya, but in the hearts of all Libyans," she said in a speech on Thursday broadcast live on Libyan television to mark the 25th anniversary of American strikes on the huge complex, which includes military barracks.
State television also showed footage of a defiant Gaddafi cruising through the streets in a green safari jacket and sunglasses, pumping his fists and waving from an open-top vehicle.
Meanwhile, NATO has launched three new airstrikes in and around the Libyan capital, striking a missile battery and two other targets.
France and Britain want to extend air strikes to the logistics and decision centres of Gaddafi's army, rather than start arming Libyan rebels, Gerard Longuet, the French defence minister, said on Friday.
Asked if it was time to send weapons to the rebels, Longuet said: "This is the reason France and Britain want to show our determination, including with strikes on military decision centres in Libya or on logistics depots which today are being spared.
"Why? Because if we want to avoid civil war... the force of the other side must be neutralised, and so the strikes we are asking for are aimed at not having to arm the insurgents. Our goal is not to organise a front, it's that Gaddafi's troops go back to their barracks," he told LCI television.
Misurata 'medieval siege'
Libyan government forces on Friday fired a hail of rockets into the besieged city of Misrata, killing at least eight people, a local doctor told Al Jazeera.
He said seven other people, including children and old people, were wounded in the attacks. Residents told Al Jazeera around 120 rockets hit the city on Friday morning.
In their article, the US, British and French leaders said Misurata was "enduring a medieval siege as Gaddafi tries to strangle its population into submission".
Aid organisations warn of a humanitarian disaster in the city, the only major rebel stronghold in western Libya, where hundreds of civilians are said to have died in a six-week siege.
Rebels have warned of an impending "massacre" by troops loyal to Gaddafi if NATO does not intensify its attacks on government forces in and around Misurata.
On Thursday, Libyan government forces also launched a heavy attack against the coastal city , with dozens of Grad-type rockets, killing at least 23 people, a rebel spokesman said.
Misurata, Libya's third-biggest city, has been the scene of major fighting between rebels and Gaddafi's forces for several weeks.
"They fired Grads at a residential area called Kasr Ahmad near the port this morning. They fired at least 80 rockets on that area," Abdelbasset Abu Mzereiq told Reuters by telephone.
He later clarified that those killed had been civilians and not rebel fighters as earlier understood. The death toll from the 90 minute artillery barrage was likely to rise, the spokesman added.
"They keep killing civilians. Yesterday we lost five civilians in the shelling and 37 were wounded."
Gaddafi loyalists were firing shells on Tripoli Street, a thoroughfare which cuts to the city centre from the western outskirts, witnesses told Al Jazeera.
The rocket assault on the residential area near the rebel-controlled port had also prevented a Qatari vessel from docking, another rebel spokesman said. It was not immediately clear what the ship was carrying.
Electricity and communications lines to the city have been cut while a rebel spokesman told Al Jazeera that the city faced food shortages.
Al Jazeera's Hoda Abdel-Hamid, reporting from Benghazi, says the situation on the ground remains grim.
"We have seen some pictures and some very graphic videos of wounds and casualties in Misurata - stuff we really can't broadcast because they're so graphic - but they do tell you about how bad the situation is in that city," she said.