The Philippines launched its newest warship on Wednesday, a former US coast guard cutter that President Benigno Aquino said would be deployed to waters at the heart of a territorial dispute with China. Aquino said the 115-metre (378-foot) Gregorio del Pilar would lead patrols in the parts of the South China Sea that the Philippines claims exclusively as its own and where exploration for potentially lucrative gas fields is underway. "The Gregorio del Pilar, named after the newest general of the Philippine revolution, will take the lead in patrols for our sovereignty, and in ensuring that our waters are crime-free," Aquino said. Aquino was speaking at navy headquarters in Manila during a commissioning ceremony for the vessel, which replaces a World War II-era destroyer as the country's top warship. The Gregorio del Pilar was acquired from the United States this year amid rising tensions between the Philippines and China in the South China Sea. Tensions escalated after the Philippines accused the Chinese navy of firing warning volleys at Filipino fishermen in the South China Sea, harassing an oil exploration vessel and putting up markers on Philippine islets. Those areas are much closer to Philippine landmass than Chinese, but China insists it has sovereign rights to virtually all of the South China Sea, even waters up to the coasts of Southeast Asian countries. Other parts of the sea, which are reputedly rich in mineral resources and straddle vital sea lanes, are also claimed by Brunei, Malaysia, Taiwan and Vietnam. The competing claims have for decades made the sea one of Asia's most dangerous potential military flashpoints. Meanwhile in Beijing, state media reported Wednesday that China has sent its largest patrol ship, the 3,000-tonne Haijian 50, to the East China Sea to guard the country's territorial rights. China has repeatedly locked horns with its neighbours Japan and Taiwan over a group of uninhabited islands -- called Senkaku in Japan and Diaoyu in Chinese -- in the East China Sea which Beijing claims are in its territorial waters. Japan and Taiwan also claim sovereignty over the area, which is similarly believed to be rich in oil and gas.