According to this Stars and Stripes article the Croatians and al-Qaida had a working relationship:
West feeling the fallout of efforts to aid Bosnian Muslims a decade ago
"Al-Qaida trained Mujahedeen to go and fight in Bosnia during the early ’90s, and bin Laden’s Services Office also maintained an office in neighboring Croatia’s capital, Zagreb." The Mujahedeen came into Bosnia from Croatia, the colonel said. "They came into Croatia at the ports of Split and Rijeka. Those were big centers." Along with the fighters, the arms pipeline came through Croatia and was funded by Third World Relief Agency, the Washington Post reported in a September 1996 story. The wartime Bosnian government depended on the Third World Relief Agency, which obtained and paid for weapons from Iran and other countries along with supplying fighters, the Post reported.