Story highlights The case stems from the fighting in Croatia's Krajina region

Ante Gotovina commanded a military district; Mladen Markac headed a police unit

Serbia's president calls the action "a political decision and not a legal ruling"

Two top Croatian commanders previously convicted of war crimes and crimes against humanity during the Balkan wars were acquitted Friday.

The International Criminal Court for the former Yugoslavia ordered the release of Ante Gotovina and Mladen Markac and reversed all of their convictions.

Gotovina and Markac participated in an ethnic cleansing operation in Croatia's Krajina region between July and September 1995, the court ruled last year..

Gotovina, a general who commanded Croatia's Split military district during the mid-1990s war that led to the disintegration of Yugoslavia, had been sentenced to 24 years in prison. Markac, who headed the Interior Ministry's Special Police, received an 18-year prison term.

But the court's Appeals Chamber found errors in the ruling, including the failure to find "the existence of a joint criminal enterprise" intent on permanently and forcibly removing Serb civilians from the Krajina region.

Serbian President Tomislav Nikolic's office issued a statement criticizing the development.

"The tribunal has made a political decision and not a legal ruling. This will continue to destabilize the situation in the region and it will open old wounds," the statement said.