Police are appealing for public assistance to help locate a missing 13-year-old boy.

Demitrious Phillips was last seen at a shopping centre on Heaths Road, in Werribee on Monday.

Police and family have concerns for him due to his age and length of time that he has been missing.

He was last seen wearing a black peaked cap, black long-sleeved shirt, camouflage pants and runners.

Police have released an image of Demitrious in the hope someone can provide information about his whereabouts.

Anyone with any information is urged to contact the Werribee Police Station on 9742 9444.