(Yicai  Global) July 18 -- China's mainland stock markets struggled throughout  today as the benchmark Shanghai and Shenzhen indexes finished at their  lowest close in a month amid a lower than usual trading volume.

The  Shanghai Composite Index closed down 1.04 percent at 2,901.18, its  lowest finish since June 17, while the Shenzhen Component Index ended  1.58 percent lower at 9,154.65, its worst close since June 26. The  ChiNext Price Index, which tracks growth enterprises listed in Shenzhen,  finished down 1.66 percent at 1,524.48.