SARAJEVO, Bosnia -- Bosnian authorities on Thursday identified two suspects arrested in connection with a fatal attack on a police station, including one already under investigation for allegedly helping to recruit fighters for the Islamic State group.

Monday's attack in the Bosnian Serb town of Zvornik left a Serb policeman and a gunman dead and two officers wounded.

Prosecutors identified the two suspects as 24-year-old Avdulah Hasanovic, and 40-year-old Kasim Mehidic. The men were arrested on Tuesday.

Hasanovic was detained last year in a sweep against Islamic extremists who allegedly recruited people to fight for IS in Syria. He was later released, but his passport has been confiscated and he has had to regularly report to authorities. The group's leader is on trial.

Radical Muslims were non-existent before the 1992-95 war in the Balkans when foreign mujahedeen arrived in Bosnia to help the Muslim Bosniaks fight against Serbs and Croats. Most of them left after the war but had managed to spread their ultra-conservative interpretation of Islam among a few thousand locals, who stand out amid the majority moderate and secular Bosnian Muslims.

Bosnian Serb police chief Dragan Lukac said the investigation so far shows the gunman Nerdin Ibric was connected to such extremists.

Experts say some 200 Bosnians are fighting in Syria. IS recruiters mostly target young, jobless men with no hope for a better future in a country with an unemployment rate of more than 40 per cent. The 24-year-old gunman fit this profile and was the son of a man who was killed during the war when Serb police from Zvornik rounded up over 700 Muslim men from the once predominantly Muslim town and executed them as part of a campaign to create a pure Serbian area.

Bosnia's Islamic Community condemned the attack and said the perpetrator's background is no excuse for committing such a crime.