The extension of SGR is expected to boost economic growth and facilitate trade across the East African Community.
Each train can carry up to 589 passengers, taking them along at speeds of up to 160 kilometres per hour.
Once complete, the link will enable passengers to travel between Mombasa Central Railway station at the CBD and Mombasa Terminus in Miritini with ease.
This is the first time new wagons have been added since the launch of the SGR in May 2017.
Kenya Railways said the increase has been necessitated by changes in the energy and petroleum sector where prices of fuel have significantly increased affecting the cost of its operations.