A subway line extension was put into trial operation Thursday in north China's Tianjin Municipality.

The extension of Subway Line 6 connects two previously operated sections, linking Meilin Road, Hexi District and Nansunzhuang, Dongli District, according to the municipal subway operator.

The line intersects with three existing subway lines, and has four interchange stations.

Tianjin began building its first subway line in the 1970s, becoming the second Chinese city to construct an underground rail link. Currently, it has five lines in operation.