The NF Railway reviewed the security scenario in the area and decided to restore the services following improvement in the situation.
All trains, including passengers and goods, ran normally, the sources said.
Unidentified gunmen on October 5 had fired at the Agartala Express near Bagetar railway station in central Assam's Dima Hasao district, following which the services had been suspended.
The attack occurred hours after the Central government decided to sign peace accord with two factions of the Dimasa tribal militant outfits led by Dilip Nunisa and Jewel Garlosa.