President Rodrigo Duterte has launched a foul-mouthed attack on the UN human rights chief, calling him “empty-headed” in a row over international criticism of the Philippine leader’s deadly drug war. Zeid Ra’ad Al Hussein, the UN High Commissioner on Human Rights, had last month said Duterte needed “psychiatric evaluation” and that his verbal attacks on a United Nations rapporteur who condemned his anti-drug crackdown could not go unanswered. Duterte won a presidential election in mid-2016 after promising to eradicate drugs in society within six months by killing tens of thousands of users and dealers. The International Criminal Court has launched a “preliminary examination” into killings in the anti-drug campaign.