Election officials say former Philippine President Rodrigo Duterte has been elected as mayor in his home city by a landslide, despite his detention by the International Criminal Court.

Candidates linked to Philippine ex-leader Rodrigo Duterte appear to have won election victories, including Duterte himself, despite him being detained for alleged crimes against humanity.

In the southern Philippine city of Davao, a spirited mayoral election campaign is in full swing, with candidates and their supporters out canvassing for votes.