RIO DE JANEIRO, June 10-- A new batch of Chinese trains designed for Rio's new subway line were started being tested on Wednesday, according to local government.

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

However, while Line 4 is still under construction, the trains will be gradually tested in Line 1 and Line 2 that have been using19 trains bought from China by Rio's subway company Metro Rio.

Luiz Fernando Pezao, Rio de Janeiro state governor, visited Wednesday the subway network's Line 4 that will be inaugurated next year.

Out of the 15 new trains, 12 are already in Rio. The other three are expected to be delivered to Metro Rio by the end of the year.