The wartime commander of Bosnian Croat forces, Slobodan Praljak, has died after he drank a liquid he said was poison seconds after UN judges turned down his appeal against a 20-year sentence for war crimes against Bosnian Muslims, a court spokesman confirms.

Key points: Slobodan Praljak claimed he was not a war criminal and opposed the conviction

Slobodan Praljak claimed he was not a war criminal and opposed the conviction Dutch police, an ambulance and a fire truck arrived at the court

Dutch police, an ambulance and a fire truck arrived at the court The tribunal was set up in 1993, has indicted 161 suspects and convicted 90

Praljak, 72, tilted back his head and took a swig from a bottle shortly after appeals judges confirmed his sentence for involvement in a campaign to drive Muslims out of a would-be Bosnian Croat ministate in Bosnia in the early 1990s.

"I just drank poison," he said.

"I am not a war criminal. I oppose this conviction."

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Presiding Judge Carmel Agius had overturned some of Praljak's convictions but left his sentence unchanged.

Judge Agius quickly halted the hearing at the International Criminal Tribunal for the former Yugoslavia.

Dutch police, an ambulance and a fire truck quickly arrived outside the court's headquarters and emergency service workers, some of them wearing helmets and with oxygen tanks on their backs, went into the court.

Spokesman Nenad Golcevski told reporters Praljak was rushed to a nearby hospital, where he died.

Croatian General Marinko Kresic told Croatian state TV he had spoken to the wife of another defendant, General Miroslav Praljak, who was in The Hague.

"She confirmed that he drank the poison …" he said.

Court to close after 90 convictions since 1993

It could not immediately be confirmed whether Slobodan Praljak had taken poison. ( AP: ICTY )

Wednesday's hearing was the final case at the ground-breaking tribunal before it closes its doors next month.

The tribunal, which last week convicted former Bosnian Serb military chief General Ratko Mladic of genocide and other crimes, was set up in 1993 while fighting still raged in the former Yugoslavia.

It indicted 161 suspects and convicted 90 of them.

The appeals judges upheld a key finding that late Croat President Franjo Tudjman was a member of a plan to create a Croat mini-state in Bosnia.

Two other suspects had also had their sentences upheld before the hearing was halted.

Croatian Prime Minister Andrej Plenkovic said on Wednesday he regretted the death of Praljak.

"His act, which we regrettably saw today, mostly speaks about a deep moral injustice towards six Croats from Bosnia and the Croatian people … we voice dissatisfaction and regret about the verdict," Mr Plenkovic said.

AP/Reuters