Powerful explosions rocked Tripoli as NATO on Wednesday pressed its air war amid Libyan charges that it has killed 718 civilians and reports that British ex-special forces soldiers are advising the rebels.NATO allies on Wednesday agreed to extend the campaign in Libya for another 90 days, prolonging the mission until late September, the alliance said.NATO Secretary General Anders Fogh Rasmussen said that NATO and partners have just decided to extend the mission for Libya for another 90 days. This decision sends a clear message to the Gaddafi regime that the western powers are determined to continue the operation to protect the people of Libya.In the Libyan capital, government spokesman Mussa Ibrahim told a news conference that 10 weeks of NATO-led air strikes authorised by the UN Security Council to protect civilians had also wounded 4,067.He warned the departure of veteran leader Muammar Gaddafi, as demanded by NATO and the G8, would be a worst case scenario for Libya.Ibrahim said, citing health ministry figures which cannot be independently verified that since March 19, and up to May 26, there have been 718 martyrs among civilians and 4,067 wounded, 433 of them seriously.He said these figures do not include Libyan military casualties, a toll the defence ministry refuses to divulge.