Bulgaria's State Agency for National Security (DANS), the national police and the border police detained 11 people in a special operation in Sofia and Pernik region, DANS said.
The agency says the group was an organised criminal gang that moved migrants from high-risk countries through Bulgaria to European Union states. Nine of those held are Bulgarians and two are foreigners.
Police and investigators searched ten addresses today. Sofia City Prosecutor's Office has opened a pre-trial investigation.
BTA recalls that on 27 October the border police detained 19 people in a raid, and prosecutors charged four of them.