MANILA, Philippines — Filipino fishermen have reported that a Chinese coast guard vessel used a water cannon to drive them away from a disputed shoal, the Philippine military chief said Monday, adding that his forces seek to avoid trouble but would respond if any country involved in regional territorial disputes uses force against Filipinos.Gen. Emmanuel Bautista said the military is investigating the Jan. 27 incident at Scarborough Shoal, a rich fishing ground off the northwestern Philippines. The shoal came under China's effective control after Philippine vessels backed off from a tense standoff with Chinese ships in the area in 2012.Chinese coast guard and surveillance ships have since guarded the shoal, chasing Filipino fishermen away if they ventured close. The Philippines has not deployed its ships to take back control of Scarborough but asked an international tribunal last year to declare China's seizure of the shoal and seven other South China Sea reefs illegal.Bautista told reporters in a forum that Philippine forces adhere to a no-confrontation policy in the disputed areas but would defend the country and its people if they are threatened."It's our policy to avoid any confrontation with anybody, in this case, the Chinese coast guard or the PLA navy," Bautista said, referring to China's People's Liberation Army.But he said that "if armed violence is used against our people, then we will have to react to the best of our ability."The Chinese Embassy in Manila did not immediately reply to a request for comment.A senior Philippine military official in charge of monitoring the disputed territories said the Chinese coast guard used a water cannon from a distance to scare off a boatload of Filipino fishermen from getting near Scarborough but they were not actually hit by the spray.The incident appeared to be isolated and no other acts of intimidation have been reported by Filipino fishermen, said the official, who spoke on condition of anonymity because he was not authorized to talk to reporters.Asked if the Philippines would lodge a protest over the incident, Bautista said Filipino officials would have to investigate before deciding what step to take.China, the Philippines and four other governments have been disputing ownership of resource-rich South China Sea territories for years. Many fear the disputes, which have sparked tensions and strained ties between the rival claimants, could set off an armed conflict.Talks between Southeast Asian countries and China aimed at forging a nonaggression "code of conduct" in the disputed region should be accelerated, U.S. Ambassador Philip Goldberg told the news forum, adding that the establishment of communication hotlines and emergency procedures could help prevent incidents.He said Washington does not take sides in the territorial disputes, but believes that China's recent imposition of fishing and aviation regulations in contested areas was illegal.Goldberg suggested that the United States would not stand by and let the situation deteriorate."We consistently state we have a national interest in the maintenance of peace and stability, respect for international law, unimpeded lawful commerce and freedom of navigation and overflight in the East China and South China seas," he said.