Friday's event was a formal inagurarl and services for the public will start on January 9.
The train service was launched from Kamakhya to Bengaluru (3,030 km) on December 25, 2016. Now it has been extended to Agartala.
According to the Northeast Frontier Railways (NFR), the train will halt at seven stations between Agartala and Guwahati and at 26 between Agartala and Bengaluru Cantonment station.
The Humsafar Express is a fully AC 3-tier service.
The NFR is now extending the railway line up to southern Tripura's bordering town Sabroom, 135 km south of Agartala.
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