Bangladesh High Commissioner to India Muhammad Imran and senior officials of railway ministries of both the countries, among others, were present during the flagging off ceremony.
Sources said the train will take nine hours to travel 513 kilometres between New Jalpaiguri and Dhaka Cantonment station. It will be operated by a diesel engine and will have four air-conditioned cabin coaches and four air-conditioned chair cars.
The Mitali Express will run two days a week- on Monday and Thursday, which will leave Dhaka Cantonment at 21:50 hours (BST).
The other two Bangladesh-India passenger trains - Maitree Express and Bandhan Express, whose operations were disrupted due to Covid-19 restrictions, resumed their services on 29 May.
Maitree Express, which began service in 2008, is the first train to run between the two countries since the partition of British India in 1947. Bandhan Express began service later that year.