A wartime commander of Bosnian Croat forces "drank poison" during a hearing at the U.N. war crimes tribunal on Wednesday at which his 20-year prison sentence was upheld, his lawyer said.
Slobodan Praljak, 72, tilted back his head and took a swing from a flask or glass as the judge read out the verdict.
"My client says he drank poison this morning," defense attorney Natasa Faveau-Ivanovic said.
"Slobodan Praljak is not a war criminal. I reject the verdict with contempt," the 72-year-old Praljak screamed, as he unscrewed a bottle he was holding and drank from it.
It was unclear whether Praljak had really consumed poison.
The presiding judge suspended the hearing and called for a doctor.
The ruling on some of the 22 counts for which the group was sentenced for up to 25 years in prison was still due to be read.
Later on Wednesday, a guard for the court appealed for calm, and confirmed to journalists that Praljak was alive. "He is receiving all necessary medical attention," he added, after AFP journalists saw medics carrying equipment rushing into the tribunal in The Hague.
Bosnian Croat leaders Jadranko Prlic, 58, Praljak, Bruno Stojic, Milivoj Petkovic, Valentin Coric and Berislav Pusic were sentenced in the first instance in 2013. The Appeals Chamber overturned some of the counts.
It was the last judgment by the International Criminal Tribunal for the former Yugoslavia (ICTY), established by the United Nations in 1993, before it closes next month. The remaining work, including appeals in the genocide cases of Bosnian Serbs Radovan Karadzic and Ratko Mladic, will be handled by the UN Mechanism for International Criminal Tribunals (MICT).
Praljak was specifically charged with ordering the destruction of Mostar's 16th-century bridge in November 1993, which judges said "caused disproportionate damage to the Muslim civilian population".
A symbol of Bosnia's devastation in the war, the iconic Ottoman-era bridge was later rebuilt. But the city saw the worst of the Croat-Muslim clashes, with nearly 80 percent of the city's east destroyed in the fighting.
Mostar, an impoverished city, and its industry never recovered from the conflict, and ethnic divisions still run deep.