Police raided more than 20 properties in southwestern Germany and arrested at least four people. The case pertains to trafficking people from the Caucasus region to work illegally and for less than the minimum wage.

Federal police in southwestern Germany raided properties in the cities of Mannheim, Karlsruhe and Worms early on Tuesday, investigating a suspected human trafficking operation, a spokesperson said.

A total of 400 officers were in action, searching 24 properties, with federal police, the public prosecutor’s office and central customs involved.

Police said at least four people had been arrested in the operation, but that a seven-person group including both men and women was under investigation and more arrest warrants were being sought.