* One Chinese ship withdrawn, two remain * Three of 8 Chinese fishing vessels leave shoal * Philippine navy sends ship to disputed area * Diplomatic efforts to resolve row proceed (Recasts, adds three Chinese fishing boats leaving, officials' comments) By Rosemarie Francisco MANILA, April 13 (Reuters) - Three Chinese fishing boats and one Chinese naval vessel left a disputed area of the South China Sea on Friday, but there was no end in sight to Beijing's territorial standoff with the Philippines, the subject of a decades-old dispute. Problems began on Sunday when Manila dispatched its largest warship, a U.S. Hamilton-class cutter, to Scarborough Shoal, a group of rocky outcrops off the main Philippine island of Luzon, after it spotted eight Chinese fishing boats anchored in the area. The shoal, which is crossed by major shipping lanes, is believed to be rich in oil and gas reserves as well as fish stocks and other comercially-attractive marine life. On Friday, Philippine officials confirmed that three Chinese fishing boats had left the area, but said five other Chinese boats remained. It was unclear whether they carried illegal catches, they added. Officials had earlier said that giant clams, coral and live sharks were illegally harvested from waters surrounding the Philippine island of Luzon. "We are watching five fishing vessels that are still collecting coral in that area," Lieutenant General Anthony Alcantara, chief of the army's northern Luzon command, told reporters on Friday. Asked if the three fishing vessels which left had carried illegal catches, he said: "I have no data on that." China also withdrew one of its three naval ships from the area on Friday, a day after a Philippine warship pulled out to be replaced by a coast guard vessel. Manila's move had been interpreted as a sign that tensions were easing as diplomats rushed to find a solution to the dispute. But on Friday the Philippine navy sent a ship into the area to back up a coast guard cutter tasked to enforce the country's maritime laws, suggesting tensions were still high. "The mandate is to support our coast guard there," Alcantara said. "Our mandate is to take care of our own people there and sovereignty." BAD WEATHER The Chinese fishermen originally said they were sheltering from bad weather. Philippine security officials had been poised to detain them soon after they were spotted but were blocked by two Chinese surveillance vessels. A third Chinese vessel arrived on Thursday at the shoal. Talks between Beijing and Manila have been held on and off since then to try to resolve the standoff. Philippine Foreign Affairs Secretary Alberto del Rosario, who has been holding talks with China's ambassador Ma Keqing, said he did not believe the Chinese boats had escaped. "I think they just went out of the lagoon because nobody was keeping them there," he told reporters. "Our Philippine fishing boats, and Chinese fishing boats are going in and out of that lagoon," Del Rosario said. "What I'm saying is that there is freedom of ingress and egress." The fact that the boats left without being intercepted by Philippine authorities could be a diplomatic tactic, Alcantara suggested. Beijing is asserting its sovereignty over the entire South China Sea, while the Philippines, Vietnam, Brunei, Malaysia and Taiwan continue to claim that portions belong to them. Del Rosario said both sides put forward proposals to resolve the dispute, but that no agreement had been reached. He gave no details on the proposals, but said he would meet again with China's ambassador on Friday evening. APPEAL FOR CALM The overseas edition of Chinese Communist Party mouthpiece the People's Daily called for calm, accusing unnamed Western countries and media of exaggerating the seriousness of the situation to sow discord between China and its neighbours. "China does not want to see the stand-off which has developed between Chinese and Philippine ships over Huangyan Island," it wrote in a front page commentary. In March last year, Chinese navy ships threatened to ram a Philippine survey vessel in another disputed area, the Reed Bank. In response, the Philippines scrambled aircraft and ships. Ill-equipped to patrol waters across the archipelago of more than 7,000 islands, the Philippines has sought closer cooperation with its chief ally, the United States, which has refocused its military attention on Asia. Manila has offered Washington greater access to airfields and its military facilities in exchange for more equipment and frequent training to enhance its military capability. Philippine and U.S. forces are due to hold a military exercise near the Reed Bank this month. (Additional reporting by Ben Blanchard in Beijing; Editing by Andrew Osborn)