Chinese Premier Li Keqiang took a ride on a "made in China" subway train deployed in Rio De Janeiro. The metropolis with a population of 6.5 million is going to host the 2016 Summer Olympics. [Photo: Xinhua]

A new batch of Chinese-produced trains designed for use in the Brazilian city of Rio de Janeiro's new subway line are now being tested.

The 15 trains are expected to be used on Line 4 of Rio's metro system.

That line is still under construction.

It's expected to be opened next year.

Of the 15 new trains, 12 are already in Rio.

The others are to be delivered before the end of the year.

Close to 20 Chinese-produced trains are already in-operation in Rio's metro system.