Ratko Mladic, the former Bosnian Serb general convicted of genocide and sentenced to life imprisonment, has died while receiving treatment at a hospital in The Hague, Netherlands. He was 83. The UN’s International Residual Mechanism for Criminal Tribunals confirmed the death, saying he died early in the day. Judge Graciela Gatti Santana ordered a full investigation into the circumstances of his death.

Known as the “Butcher of Bosnia,” Mladic had been ill for a long time and suffered several strokes. A UN doctor had said earlier this month that he could die at any time or within weeks, while his renewed request for release was rejected. In 2017, a UN tribunal sentenced him to life for genocide and war crimes committed during the Bosnian war.

Mladic was convicted over the 1995 killing of at least 8,000 Muslims in the UN-declared safe area of Srebrenica. The source describes the massacre as Europe’s worst genocide since World War II. Munira Subasic of Mothers of Srebrenica expressed sorrow but said many Bosnian Serbs still deny his crimes, while Human Rights Watch said his death renewed the need for justice, truth and reparations in the Western Balkans.