(CNN) -- Ratko Mladic, who is on trial on charges he masterminded an army campaign to cleanse Bosnia of Croats and Muslims, was taken to the hospital Thursday as a precautionary measure, a court spokeswoman said.
"Proceedings were adjourned because he wasn't feeling well," said Nerma Jelacic, a spokeswoman for International Criminal Tribunal for the former Yugoslavia. She did not release any details about his condition.
Mladic, whose trial began at the Hague in May, is accused of orchestrating a campaign of ethnic cleansing during the bloody civil war that ripped apart Yugoslavia. He has been indicted on 11 counts of genocide, war crimes and crimes against humanity in the 1992-95 war.
His trial is taking place in The Hague at the International Criminal Tribunal for the former Yugoslavia, a court established to try those responsible for atrocities during the war.
In May, prosecutor Dermot Groome laid out details of the case against Mladic, saying that ethnic cleansing was not a byproduct of the war, but a specific aim of the Bosnian Serb leadership.
He said he would show that Mladic was directly responsible for atrocities carried out by his forces, which were fighting for control of land in ethnically mixed Bosnia.
Mladic eluded authorities for nearly 16 years until his capture in May 2011, when police burst into the garden of a small house in northern Serbia.
Though he was carrying two handguns, he surrendered without a fight and was extradited to the Netherlands.
In the three decades leading up to the violent splintering of Yugoslavia, Mladic rose rapidly through the ranks of the Yugoslav army. In 1991, he served as a front-line commander spearheading Serb forces in a yearlong war with Croatia.
By the time he took to Bosnia's battlefields, he had become a hero to many Serbs, seen as a defender of their dwindling fortunes.
In May 1992, Bosnia's Serbian political leaders picked him to lead the assault on their Muslim enemies who clamored for independence.
Mladic wasted no time galvanizing his heavily armed forces in a siege of Sarajevo, cutting the city off from the outside world. Serb forces pounded the city every day from higher ground positions, trapping Sarajevo's ill-prepared residents in the valley below.
As the war ended in the fall of 1995, Mladic went on the run.
Shortly after Mladic was sent to The Hague last year, authorities nabbed former Croatian Serb rebel leader Goran Hadzic. He was the last Yugoslav war crimes suspect at large.