MANILA – The Philippine government on Monday vowed a “fair and thorough” probe into the killing of two Vietnamese fishermen off Pangasinan in South China Sea, even as it noted that the foreigners encroached on the country’s 200-nautical mile exclusive economic zone.

The Armed Forces’ Northern Luzon Command said they chased the Vietnamese fishermen who evaded arrest for fishing illegally in waters off Bolinao, Pangasinan. The foreigners allegedly fought naval authorities, prompting a shoot-out.

Presidential Spokesperson Ernesto Abella noted that the Vietnamese fishing boats “were seen fishing 34 nautical miles off Cape Bolinao in Pangasinan well within exclusive economic zone.”

The bodies of the 2 slain Vietnamese nationals were brought to a morgue, while Filipino authorities took custody of 5 companions of the slain Vietnamese.

“The Department of Foreign Affairs is closely coordinating with the officials of the Vietnamese Embassy in Manila to update them on the developments and to facilitate their access to the five other Vietnamese fishermen taken into custody by the Philippine Navy,” Abella said.

Manila’s response to the illegal fishing activities by the Vietnamese nationals and its description of the incident appear to be in stark contrast with how it handles issues involving Chinese fishermen, who are usually backed by Beijing, in the disputed South China.

President Rodrigo Duterte has been criticized for his response on perceived Chinese aggression in the South China Sea, where Beijing has built several artificial islands to assert its claim to almost the entire body of water.

Last month, opposition lawmaker Gary Alejano and Supreme Court Senior Associate Justice Antonio Carpion claimed that several Chinese ships were spotted in Sandy Cay, located some 2.5 miles off Pag-asa Island.

Carpio described the incident as an invasion by the Chinese, but the DFA, led by Foreign Affairs Secretary Alan Peter Cayetano, and Duterte downplayed this.

Since assuming the presidency, Duterte has sought to downplay Manila’s maritime dispute with Beijing, in pursuit of warmer ties with the economic giant.

The President has also chosen to set aside Manila’s arbitration victory against Beijing which invalidated the latter’s 9-dash line claim to the West Philippine Sea.

China claims almost the entire South China Sea, through which about $3 trillion worth of trade passes each year. Brunei, Malaysia, the Philippines, Taiwan and Vietnam also have claims to parts of the sea.