BELGRADE, Serbia (AP) — Serbia's new chief war crimes prosecutor has filed a request to resume the landmark trial against eight former Bosnian Serb police officers charged with taking part in the 1995 Srebrenica massacre.

The proceedings have been halted after an appeals court ruled the charges were invalid because they were filed during the time when Serbia did not have a chief war crimes prosecutor.

Serbia's rights groups have criticized the ruling, warning of state obstruction of war crimes trials in the Balkan country seeking to become a member of the European Union.

The war crimes prosecutor's office said Monday the request to resume the trial was filed last week by the chief prosecutor Snezana Stanojkovic.

The Srebrenica trial is considered a key test of Serbia's pledge to deal with its wartime past.