A Nato missile strike killed Muammar Gaddafi's youngest son and three grandchildren, but the Libyan leader survived, a Libyan government spokesman said this morning.
Gaddafi and his wife were in the Tripoli house of his 29-year-old son Saif al-Arab Gaddafi, when it was hit by at least one bomb dropped from a Nato warplane yesterday, according to Libyan spokesman Moussa Ibrahim.
"The leader himself is in good health," Ibrahim said. "He was not harmed. The wife is also in good health."
Saif al-Arab Gaddafi was the sixth son of Gaddafi and brother of the better known Saif al-Islam Gaddafi. The younger Gaddafi had spent much of his time in Germany in recent years.
"The attack resulted in the martyrdom of brother Saif al-Arab Gaddafi, 29 years old, and three of the leader's grandchildren," Ibrahim said. He said Saif al-Arab was a student at a German university but had not yet completed his studies.
Saif 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.
Journalists taken to the walled complex of one-storey buildings in a residential Tripoli neighbourhood saw heavy bomb damage. The blast had torn down the ceiling of one building and left a huge pile of rubble and twisted metal on the ground.
Ibrahim said the air strike was an attempt to "assassinate the leader of this country", which he said broke international law.
Nato denied targetting Gaddafi but said it struck a command and control centre.
British defence secretary Liam Fox and US defence secretary Robert Gates also told reporters at the Pentagon on Tuesday that Nato planes were not targeting Gaddafi specifically, but would continue to attack his command centres.
Heavy bursts of gunfire were heard in Tripoli after the attack.
Gaddafi had seven sons and one daughter. Saif al-Arab was the youngest son.
The Libyan leader also had an adopted daughter who was killed in a 1986 US air strike on his Bab al-Aziziya residential compound, which was separate from the area struck yesterday.
That strike came in retaliation for the bombing attack on a German disco in which two US servicemen were killed. The US at the time blamed Libya for the disco blast.
Saif's mother is Safiya Farkash, Gaddafi's second wife and a former nurse.
Yesterday's fatal air strike came just hours after Gaddafi called for a mutual ceasefire and negotiations with Nato powers to end the six-week bombing campaign.
In a rambling pre-dawn speech he said "the door to peace is open".
"You are the aggressors. We will negotiate with you. Come, France, Italy, UK, America, come to negotiate with us. Why are you attacking us?" he asked.
He also railed against foreign intervention, saying Libyans had the right to choose their own political system, but not under the threat of Nato bombings.
In Brussels, a Nato official said before yesterday's fatal strike that the alliance needed "to see not words but actions", and vowed the alliance would keep up the pressure until the United Nations Security Council mandate on Libya was fulfilled.
Nato has promised to continue operations until all attacks and threats against civilians have ceased, all of Gaddafi's forces have returned to bases and full humanitarian access is granted.
The Nato official noted that Gaddafi's forces had shelled Misrata and tried to mine the city's port just hours before his speech.
"The regime has announced ceasefires several times before and continued attacking cities and civilians," the official said.
"All this has to stop, and it has to stop now.".
Rebel leaders have said they will only lay down their arms and begin talks after Gaddafi and his sons step aside. Gaddafi has repeatedly refused to resign.
A rebel spokesman, Jalal al-Galal, called the ceasefire offer a publicity stunt.
"We don't believe that there is a solution that includes him or any member of his family. So it is well past any discussions. The only solution is for him to depart," he said.
Rebels honked horns and chanted "Allahu Akbar" - 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.
White House spokesman Shin Inouye declined to comment on yesterday's developments in Libya, referring questions to Nato. Alliance officials in Brussels said a statement would be issued later.
In Misrata, rebel fighter Abdel-Aziz Bilhaj, 22, welcomed yesterday's attack, saying it would make Gaddafi think twice about how he dealt with his people.
"It could make him more willing to back down on certain parts of his plan," he said.
Medic Abdel-Monem Ibsheir considered the strike a form of justice.
"Gaddafi was not far away, meaning he's not safe," he said. "It's just like our children getting hit here. Now his children are getting hit there."