COTABATO CITY, Philippines — A post office employee in Cotabato City was shot dead by a still unidentified gunman Monday evening, police said.

The victim was identified as 40-year-old Saidali Cumilao.

Investigation showed that Cumilao was standing in front of a department store along Bonifacio Street in Poblacion 6 when the suspect approached him and suddenly shot him in the back.

Police have yet to identify the motive behind the killing but authorities are looking if the incident was work-related.

“Iniimbestigahan pa natin ‘yung motibo, tinitingnan din natin kung may kinalaman ba ang trabaho niya sa pagpatay sa kanya,” Sr. Supt. Rolen Balquin said.

Recovered from the crime scene was an empty shell believed to be from a .45-caliber pistol.

Further investigation is still ongoing.