(WOMENSENEWS)–The Department of Defense concluded in a recent report that U.S. soldiers visiting brothels in South Korea may have facilitated sex trafficking in the region, The Associated Press reported Tuesday.

The report is the result of an investigation demanded by 13 members of Congress more than a year ago. The Defense Department pointed to military misperceptions that hard evidence was needed to report suspicious activities.

As a result, “commanders sometimes did not take the necessary steps to place establishments off-limits” to U.S. soldiers and the situation was exacerbated by friendly relations between military police and bar owners.

Investigator Joseph E. Schmitz detailed several recommendations to combat the situation in South Korea, including educating U.S. troops on how to identify trafficking, improving on-base entertainment facilities, and coordinating efforts with local law enforcement, according to The Associated Press.

A September 2002 report from the International Organization for Migration said that since the mid-1990s, more than 5,000 women have been trafficked into South Korea for sexual services for United States service personnel.