Serbian authorities have arrested five suspected people smugglers charged with helping over 140 migrants try to reach neighboring Bosnia by crossing the Drina River in boats, the prosecutors office said Wednesday. The group had been smuggling migrants in buses since November from the Serbian capital of Belgrade to the border town of Ljubovija before sending them in boats over the Drina River, which runs between the two countries, the prosecutors statement said. No details were released about the migrants. The group was led by a Syrian national and is believed to have been paid some 17,000 euros ($18,000) for their activities. Authorities are searching for one more suspect, reported The Associated Press. Thousands of people fleeing war and poverty have been stuck in Serbia and other Balkan countries while trying to reach Western Europe. Once in Bosnia, migrants try to cross into Croatia, a member of the European Union.