A police spokeswoman told The Local that nine people – a woman and eight men – believed to be illegal immigrants, were also found on the raided properties.
They were being interviewed Wednesday, the spokeswoman said. It appeared they were headed for France or Britain but were using Germany as a transit country.
“There was no sign that they were abused or were going to be forced into prostitution,” she told The Local. “They were just people trying to move to another country to live.”
In the massive operation, 250 officers from the Berlin and federal police simultaneously raided 17 locations, 10 of which were in Berlin, with the others in Saxony and Brandenburg.
The three men arrested, also of Vietnamese origin, were allegedly the ringleaders of the organisation, which is believed to span Europe. Europol, or the European Police Office, were also involved in the operation, the spokeswoman said.
The German police had been investigating the gang since the middle of last year, but it was not known how many people might have been smuggled through Germany, the spokeswoman said.