In Libya, NATO forces today pounded Tripoli hours after Britain's top diplomat met rebel chiefs. Russia has voiced concerns that the alliance's military operation is sliding towards a land campaign. Warplanes launched intensive air raids on the Libyan capital and its eastern suburbs. Several explosions were heard, as NATO kept up its pressure on Col. Muammar Gaddafi's forces.British Foreign Minister William Hague yesterday met leaders of rebels who have been fighting to oust Gaddafi after NATO deployed attack helicopters for the first time. He told reporters that Britain would also support de-mining efforts in Misrata, the main rebel-held city in western Libya, and deliver more equipment, uniforms, and bullet-proof jackets to the rebel fighters.