BERLIN (Reuters) - Police raided 20 flats in Berlin and Brandenburg on Tuesday and arrested three men suspected of being members of a gang smuggling Vietnamese people into Germany, officers said.

The men - two aged 57 and 35 from Vietnam and one 26-year-old German - were suspected of arranging fake marriages and counterfeit paternity certificates to help people get residency permits in Germany, police said.

Officers seized wedding rings, identity documents, phones and more than 26,000 euros ($30,000) in cash, police added.

Investigations into the suspected gang started in March 2017 and have so far identified 10 German and Vietnamese suspects, the force said.