A Filipino migrant worker was shot dead by an unidentified gunman in Cabuyao City in the Philippines.

At 5.15pm on Saturday, Mario Csar J. Fajardo, 39, was with his 20-year-old son Joshua Fajardo in a motorshop when an unidentified gunman entered and shot Fajardo in the head, the Manila Bulletin reported.

According to police, Fajardo was with his son and their helper Shane Louis Chan, 23, to have their vehicle checked at the motorshop when the incident happened.

A mechanic named Quaioit Alzona, 29, also witnessed the incident and said the gunman ran away after shooting Fajardo in the head.

The police found only bullet casings at the crime scene but the motive for the killing was not known.