Libyan leader Col Muammar Gaddafi has vowed to remain in the country "dead or alive" in an audio message on state TV. He called on his supporters to defy the continuing Nato air and missile strikes and gather at his compound in Tripoli. Col Gaddafi said he would welcome death because martyrdom would be a "million times better" than surrender. The statement came hours after Nato carried out one of its heaviest daytime raids on the capital so far, with more than 20 air strikes by low-flying jets. The Libyan government acknowledged that military installations belonging to the Republican Guard had been targeted. Meanwhile, China and Russia are involved in separate diplomatic efforts to try to end the conflict. Libyan Foreign Minister Abdul Ati al-Obeidi is visiting Beijing, and a Russian envoy is in Benghazi to meet the rebels.