Those arrested in the operation conducted yesterday included Sibaram Patnaik (28), identified as the gang leader, who is involved in at least a dozen cases, police said.
In the last year, GRP had arrested another three members of the gang after a train robbery committed on September 9, 2015.
At least six miscreants looted cash and other valuables from passengers traveling in Bhubaneswar-Palasa DMU train between Narsinghpur and Jagannathpur near Berhampur railway station in Ganjam district in June.