A spokesperson for Philippine President Rodrigo Duterte says the leader will not cooperate with a probe by the International Criminal Court into the thousands of alleged extra-judicial killings in his country, all part of its bloody war on drugs.The ICC's chief prosecutor asked the court on Monday (June 14) to open the case, which she has previously said could uncover crimes against humanity, and referred to a series of Reuters investigations in her preliminary findings.On Tuesday (June 15), families of some of the dead cheered the court's move.Normita Lopez's 23-year-old son was killed in 2017 when he allegedly resisted arrest."If we filed the case against Duterte here, nothing would happen. Since he's the president he can manipulate everything. He can do anything to avoid getting sued and imprisoned. When I heard the news about the ICC I became more hopeful."Philippine authorities say over 6,100 suspected drug dealers have been killed in the five years of the campaign, all of whom violently resisted arrest. Rights groups; however, say many were summarily executed.A series of Reuters investigations in 2016 and 2017 exposed some of the brutal deaths. A Duterte representative held a press conference Tuesday:"I believe that the decision to move forward into a formal investigation stage is legally erroneous, politically motivated. It is legally erroneous because in the first place the ICC has no jurisdiction over the subject matter of crimes against humanity as alleged in her information against President Rodrigo Roa Duterte. Secondly, the case even for purposes of formal investigation, is barred by the principle of complementarily. And thirdly, the investigation is not pursuant or in aid of substantial justice."Duterte is popular at home and widely supported for his tough stance on crime. The Phillipines ended its membership with the ICC in 2018.