TRIPOLI (AFP) - Nato Wednesday extended its Libyan air war by three months and said the departure of Moamer Gaddafi is only a question of time, as the strongman's oil minister reportedly defected to the rebellion. Hours after Nato-led aircraft launched new raids on Tripoli, ambassadors of the military alliance meeting in Brussels decided to renew the mission for another 90 days to late September. "This decision sends a clear message to the Gaddafi regime. We are determined to continue our operation to protect the people of Libya," said NATO Secretary General Anders Fogh Rasmussen. "We will sustain our efforts to fulfil the United Nations mandate" to defend civilians from Gaddafi's forces, he said in a statement, adding: "We will keep up the pressure to see it through." NATO, whose current campaign expires on June 27, has intensified its air raids in recent weeks with daily strikes on command and control bunkers in Tripoli to prevent Gaddafi from crushing a revolt that began in mid-February. Wednesday's decision would give individual nations time to prepare their contributions for the next 90 days, a NATO diplomat said. "There were very positive signs that nations will extend with the appropriate number of resources," the diplomat said. Meanwhile, a commission of inquiry set up by the UN Human Rights Council said Wednesday that both Libyan leader Moamer Gaddafi's regime and opposition forces have committed war crimes in their conflict. "In accordance with its mandate to look also at crimes committed in Libya, the commission has ... reached the conclusion that crimes against humanity and war crimes have been committed by the government forces of Libya," said the commission in a statement. "The commission received fewer reports of facts which would amount to the commission of international crimes by opposition forces, however did find some acts which would constitute war crimes," it added. The 47-member UN Human Rights Council set up the investigation into suspected crimes against humanity in February after Gaddafi's regime dispatched Libya's army and air force to fire on civilians. Led by former UN war crimes investigator Cherif Bassiouni of Egypt, the panel of investigators also includes Jordanian lawyer Asma Khader and Canadian Philippe Kirsch, a former judge and president of the International Criminal Court. In Rome, news agency ANSA reported that Libyan Oil Minister Shukri Ghanem announced Wednesday he had resigned and left Libya to join the uprising against Gaddafi "to fight for a democratic country." "I can't work in this situation so I have left my country and my job to join the choice made by young Libyans to fight for a democratic country," he said in Rome, following weeks of rumours and denials about his defection.