MANILA (Reuters) - The Philippines will not allow visits by the United Nations to investigate its bloody war on drugs, its foreign minister said on Wednesday, calling its human rights experts “bastards” who had already demonstrated prejudice.

The United Nations Human Rights Council approved a resolution in July to compile a comprehensive report on President Rodrigo Duterte’s three-year crackdown, during which at least 6,700 people have been killed in what police say were shootouts with dealers who resisted arrest.

Thousands of mostly urban poor drug users have also been killed, many in mysterious circumstances. Human rights groups accuse police of systematic cover-ups and summary executions of anyone associated with drugs, which police reject.

Asked in a television interview if U.N. investigators would be allowed to work in the Philippines, Foreign Secretary Teodoro Locsin said: “No. Because they have already prejudged.”