Philippines' Duterte says he may impose martial law if drug problem

Philippine President Rodrigo Duterte said he has sworn to protect the country against all threats, including drugs, which he said has affected about 4 million people. (Photo: AFP)

Manila: Philippine President Rodrigo Duterte has said he would impose martial law if the drug problem became "very virulent", just a month after dismissing as "nonsense" any suggestion he might do so. 

Duterte has made a brutal war on drugs a central pillar of his administration since he took office in the middle of last year.