The eight persons were nabbed yesterday from separate passenger trains for allegedly indulging in the ganja trade.
The raids and checking in trains and at platforms is part of a drive against illegal transport and possession of drugs and other psychotropic substances, said DGP (Telangana Railways and Road Safety) T Krishna Prasad.
The arrested accused procured the ganja from Odisha, Visakhapatnam and supplied it in Maharashtra.
Three cases were registered under relevant sections of NDPS by the Government Railway Police, Secunderabad. Further probe is on.