The Philippine president has called for calm amid an outcry after a Chinese vessel hit a Philippine fishing boat, which sank and put 22 fishermen in danger in the disputed South China Sea.

President Rodrigo Duterte said Monday the June 9 incident at Reed Bank was a "little maritime accident" between two vessels that should be investigated, and that China's side should be heard.

Duterte's reaction contrasted with that of some of his own officials, including the defense chief, who strongly condemned the Chinese vessel for sailing away as the fishing boat sank at night.

Philippine officials said a Vietnamese fishing vessel rescued the Filipinos, who were later brought home by a Philippine navy ship.