The Philippines is on edge over reports that the International Criminal Court will issue an arrest warrant for former President Rodrigo Duterte over his "war on drugs", a controversial policy that killed thousands of Filipinos when he was in office.

The Philippines said former President Rodrigo Duterte has been arrested by police after the International Criminal Court issued an arrest warrant following an investigation into his deadly drug war.

Former Philippine President Rodrigo Duterte was arrested by police at Manila's international airport Tuesday on order of the International Criminal Court in connection with a case of crime against humanity filed against him,