A dozen Bosnian men have gone on trial on charges of fighting with the Islamic State group in Syria and Iraq.

Prosecutors allege the defendants, whose trial opened Thursday, fought with the Islamic State group in Syria and Iraq in the second half of 2013 and in 2014.

The indictment states they entered Syria illegally from Turkey to "participate in terrorist activities....and fight on the side of the Islamic State" group.

Some of the defendants are also charged with illegal production, possession and trafficking of weapons and explosives.

Bosnia introduced jail terms of up to 10 years in 2014 for citizens who fight in foreign conflicts or who recruit fighters for international wars.