MANILA (AFP) - Two Swiss nationals have been shot dead in a southern Philippine resort town, the police said on Monday.

The victims, 67-year-old Mr Robert Erich Loever and 78-year-old Mr Baltazar Johann Erni, had just stepped out from a beach resort at 1pm on Sunday in Opol town, Misamis Oriental province, when unidentified gunmen shot them in the head, municipal police chief Senior Inspector Alwin Baclao said.

The assailants fled on foot, Mr Baclao said, according to the victims' two female companions who witnessed the attack.

The police ruled out robbery as motive after the suspects ran away without taking the victims' belongings, Mr Baclao said, adding an investigation was underway. Criminal gangs are known to operate in the southern Philippines, prompting China last month to warn its citizens against travelling to the area.