The Philippines on Wednesday condemned the "cowardly action" of a suspected Chinese fishing vessel accused of abandoning a Filipino fishing crew after a collision in the disputed South China Sea. The boat on Sunday hit a Filipino craft anchored near Reed Bank -- claimed by both Manila and Beijing -- causing it to sink and leaving 22 crewmen "to the mercy of the elements", said defence secretary Delfin Lorenzana. Although Philippine President Rodrigo Duterte has largely set aside the bitter dispute with Beijing over the resource-rich waterway, Manila does sometimes protest against Chinese action. "We condemn in the strongest terms the cowardly action of the suspected Chinese fishing vessel and its crew for abandoning the Filipino crew," Lorenzana said in a statement. "This is not the expected action from a responsible and friendly people." Lorenzana called for an investigation into the collision, and for "diplomatic steps" to prevent a repeat of the incident. However, Philippine defence department spokesman Arsenio Andolong told AFP the agency had yet to confirm whether the vessel was Chinese-registered, adding it was the Filipino fishermen who identified it as such. The defence chief also thanked the crew of a Vietnamese fishing vessel in the vicinity which he said brought the Filipinos to safety. Like the Philippines, Vietnam has partial claims over the South China Sea, where Beijing has staked "indisputable sovereignty" and built artificial islands with military facilities and airstrips. Taiwan, Brunei and Malaysia also have claims in the area. Competing claims over the South China Sea is a point of regional contention because trillions of dollars of goods pass through it, and rich petroleum reserves are thought to sit deep beneath its waters. Reed Bank is about 150 kilometres (93 miles) off the Philippine island of Palawan. It is within Manila's 200-nautical-mile exclusive economic zone and far from China's nearest major landmass. In 2011, the Philippines accused Chinese vessels of harassing an exploration vessel off Reed Bank. Manila won a key 2016 ruling against China's claims in the waterway, but Duterte opted to set it aside to court Chinese investment and trade. But Duterte in May warned that the South China Sea was becoming a "flashpoint". "I love China... but it behooves upon us to ask, 'is it right for a country to claim the whole ocean'?" he asked.