Amid tense courtroom scenes, prosecutors at the former Yugoslavia war crimes tribunal say the evidence shows "beyond reasonable doubt" that Ratko Mladic implemented a campaign to exterminate Muslims, Croats, and other non-Serbs during the 1992-1995 war in Bosnia-Herzegovina.
Prosecutors made the statement as the trial of the ex-Bosnian Serb military chief got under way on May 16 at the international criminal tribunal in The Hague in the Netherlands.
Mladic, 70, is facing 11 counts of genocide, war crimes, and crimes against humanity. He has denied wrongdoing.
The former Bosnian Serb military chief appeared defiant as he entered the courtroom, flashing a thumbs-up and clapping his hands to supporters.
During the hearing, he made eye contact with one of the Bosnian Muslim women in the audience and ran a hand across his throat.
The gesture led the presiding judge to hold a brief recess and order an end to "inappropriate interactions."
In his opening statement, prosecutor Dermot Groome said that he would "present evidence that will show beyond reasonable doubt the hand of Mr. Mladic in each of these crimes."
Mladic is accused of commanding the 1995 massacre of some 8,000 Muslim men and boys in the Bosnian enclave of Srebrenica, an event which is considered to be Europe's worst atrocity since World War II.
He is also charged with orchestrating the 44-month siege of Sarajevo by Bosnian Serb forces that sparked the war.
The conflict left an estimated 100,000 people dead and more than 2.2 million displaced.
Prosecutor Groome maintained that Mladic had helped lead the campaign to slaughter Muslims and other non-Serbs in Bosnia as part of a scheme to create a "Greater Serbia."
"Four days ago marked two decades since Ratko Mladic became the commander of the main staff of the army of Republika Srpska, the VRS, an army created, at least in name, on that day," Groome said. "On that day, Mladic began his full participation in a criminal endeavor that was already in progress.
"On that day, he assumed the mantle of realizing, through military might, the criminal goals of ethnically cleansing much of Bosnia."
Mladic has refused to enter pleas to the charges, but he has denied wrongdoing, saying he acted to defend Serbs in Bosnia.
He has dismissed the charges against him as "monstrous" and says he is too ill to stand trial.
The court has entered a "not guilty" plea on his behalf.
Experts say the trial could last up to three years. If convicted, Mladic faces a maximum sentence of life in prison.
Radovan Karadzic, the Bosnian Serbs' wartime political leader and associate of Mladic, is already undergoing trial at the same court.
Both men were indicted together in 1995 and face identical charges. Their cases were split when Karadzic was captured in Serbia in 2008 and taken to The Hague.
Mladic was captured three years later, also in Serbia, after 16 years as an indicted fugitive, most of which he spent in hiding.
Based on reporting by AP, AFP, and Reuters