THE HAGUE, Oct 2, 2008 (AFP) - The war crimes trial of former Yugoslav army chief Momcilo Perisic opened at the UN tribunal in The Hague on Thursday.

Perisic, 64, is the most senior Yugoslav army officer to face trial over events in Bosnia and Croatia in the 1990s Balkans wars.

He has pleaded not guilty to 13 counts of war crimes and crimes against humanity allegedly committed when he was chief of the general staff of the Yugoslav army from August 1993 to November 1998.

The charges include murder, persecution on political, racial or religious grounds, extermination, inhumane acts and attacks on civilians.

Many charges stem from the 44-month siege of the Bosnian capital, Sarajevo, in which thousands of civilians died, and the 1995 massacre of some 8,000 Muslim men and boys in the Bosnian town of Srebenica.

He stands accused over cluster bomb attacks on the Croatian capital Zagreb in May 1995 in which seven civilians died and at least 194 were injured.

Perisic served as army chief under former Yugoslav president Slobodan Milosevic.

Several of the former general's subordinates have been convicted by the tribunal, but Bosnian Serb general Ratko Mladic has been on the run since being indicted 13 years ago over the Srebrenica massacre and other crimes.

Perisic's trial was to have started Wednesday, but was delayed due to a procedural glitch in naming the judges.