SARAJEVO (Reuters) - Bosnia, Serbia, Austria and Germany have arrested more than a dozen people in a joint swoop on a major people-trafficking gang that forced women into prostitution in Western Europe, police said on Thursday.

"We believe that we have broken a very important criminal ring," Vahidin Šahinpašić, head of organized crime prevention at Bosnia's State Investigation and Protection Agency (SIPA), told reporters in the capital Sarajevo.

He said SIPA had arrested eight members of organized criminal groups involved in cross-border human trafficking and prostitution, and another three were detained in Serbia.

A number of young women from Bosnia and Serbia were forced into prostitution and their documents confiscated after being told they could count on regular jobs in Austria and Germany, and some Ukrainian women were secreted similarly into Bosnia.

Croatia was also part of the joint police operation but is not known to have arrested anyone thus far, Šahinpašić said.

Since the end of the 1990s wars in former Yugoslavia, arms- and people-smuggling has become rampant in the corruption-ridden Balkans. More recently, law enforcement agencies throughout the region have stepped up cooperation to root out organized crime.

(Reporting by Daria Sito-Sucic; Editing by Aleksandar Vasovic and Mark Heinrich)