NATO's attack on a Gaddafi family compound in a residential area of Tripoli late Saturday signalled escalating pressure on the Libyan leader who has tried to crush an armed rebellion that erupted in mid-February. Libyan officials denounced the strike as an assassination attempt and a violation of international law.
It also drew criticism from Russia, which accused the alliance of going beyond its U.N. mandate to protect Libyan civilians by trying to kill Gaddafi. "More and more facts indicate that the aim of the anti-Libyan coalition is the physical destruction of Gaddafi," said Konstantin Kosachyov, a Russian lawmaker who often serves as a mouthpiece for the Kremlin's views on foreign affairs.
The alliance acknowledged that it had struck a "command and control building," but insisted all its targets are military in nature and linked to Gaddafi's systematic attacks on the population.
"It was not targeted against any individual," NATO spokeswoman Carmen Romero said Sunday, adding the report of the deaths remained unconfirmed.
British Prime Minister David Cameron, without confirming fatalities, also told the British Broadcasting Corp. that the strike was in line with the U.N. mandate to prevent "a loss of civilian life by targeting Gaddafi's war-making machine."
The attack struck the house of one of Gaddafi's younger sons, Seif al-Arab, when the Libyan leader and his wife were inside, said Libyan government spokesman Moussa Ibrahim. Seif al-Arab, 29, and three of Gaddafi's grandchildren, all younger than 12, were killed.
Journalists taken to the walled complex of one-story buildings saw heavy bomb damage. The blast had torn down the ceiling of one building. Dust and smoke rose from the rubble, which included household items such as smashed toilet bowls, bathroom sinks and furniture among the broken walls and demolished floors.
When news of the deadly strike spread, rebels honked horns and chanted "Allahu Akbar" or "God is great" while speeding through the western city of Misrata, which Gaddafi's forces have besieged and subjected to random shelling for two months, killing hundreds. Fireworks were set off in front of the central Hikma hospital, causing a brief panic that the light would draw fire from Gaddafi's forces.
Some rebels questioned the veracity of the claim, saying the regime could be trying to discredit the international military campaign.
"We don't know if it is true or not because Gaddafi is a liar. He is probably trying to put pressure on international community. I will only believe it if you put the body in front of me," said Khaled al-Urfi, a 34-year-old metalworker.
Gaddafi, who has been in power for more than four decades, has fought fiercely to put down an uprising against his regime that began with protests inspired by a wave of Mideast unrest and escalated into an armed rebellion. But the two sides have been locked in a stalemate, with Gaddafi holding much of the western half of the country and the rebels maintaining their eastern stronghold.
NATO warplanes have been carrying out airstrikes in Libya for the past month as part of a U.N. mandate to protect Libyan civilians.
On Sunday morning, Gaddafi's troops shelled Misrata's port as a Maltese aid ship, the Mae Yemanja, unloaded food and medical supplies, said Ahmed al-Misalati, a truck driver helping move the cargo.
"We were still working this morning when they started firing rockets," said al-Misalati. "Some fell in the ocean, some on the pavement, some in the warehouses, and in the water in front of the boat."
The boat quickly embarked back to sea, he said.
Last week, regime loyalists attempted to mine Misrata's harbor to close the besieged city's only link to the world.
Moammar Gaddafi and his wife, Safiyah, were in Seif al-Arab's house in the capital's Garghour neighbourhood when it was hit by at least one bomb dropped from a NATO warplane, according to Ibrahim.
Seif al-Arab Gaddafi, was one of the youngest of Gaddafi's seven sons and brother of the better known Seif al-Islam Gaddafi, who had been touted as a reformist before the uprising began. The younger Gaddafi had spent much of his time in Germany in recent years and was not involved in Libyan power structures as were many of his siblings.
Seif al-Arab, who studied and partied for years in Munich, had several run-ins with law enforcement there.
In 2007, he even saw his house and hotel suite raided by police over allegations of illegally possessing weapons despite his claims of enjoying diplomatic immunity.
Between November 2006 and July 2010 police led investigations against Gaddafi's son on ten accounts, ranging from speeding incidents to bodily harm and possession of illegal weapons, Bavaria's state justice ministry confirmed last month.
All the investigations against him, however, were dropped.
German media reported that Gaddafi's son returned to Libya in February and Bavaria's Interior Ministry later said he had been declared a persona-non-grata.
Seif al-Arab "was playing and talking with his father and mother and his nieces and nephews and other visitors when he was attacked for no crimes committed," Ibrahim said.
The government spokesman said the airstrike was an attempt to "assassinate the leader of this country," which he said violated international law. "The leader himself is in good health," Ibrahim said.
In addition to his eight biological children, Gaddafi also had an adopted daughter who was killed in a 1986 U.S. airstrike on his Bab al-Aziziya residential compound -- retaliation for the bombing attack on a German disco in which two U.S. servicemen were killed. The U.S. at the time blamed Libya for the disco blast.
Venezuelan President Hugo Chavez, a Gaddafi ally, condemned Saturday's deadly strike, calling foreign military intervention in Libya "madness." He said he believes "they order they've given is to kill Gaddafi.
In Misrata, rebel fighters were rejoicing.
Standing outside an improvised triage unit in a tent in the parking lot, medic Abdel-Moneim Ibsheir considered the strike a form of justice.
"Gaddafi was not far away, meaning he's not safe," he said as occasional explosions could be heard throughout the embattled city. "It's just like our children getting hit here. Now his children are getting hit there."
In Tripoli, dozens danced, waved and clapped in unison at the Bab al-Aziziya compound early Sunday to show support for the regime. Heavy bursts of gunfire were heard in Tripoli after the attack.
The fatal airstrike came just hours after Gaddafi called for a mutual cease-fire and negotiations with NATO powers to end a six-week bombing campaign. NATO rejected the offer, saying the alliance needed "to see not words but actions."