From the Chinese press

Probe freak metro incident

A train on Shanghai's subway Line 10 ran in the opposite direction on July 28 because of a mix-up in communication during the upgrading and debugging of the train control signal, according to Shanghai Shentong Metro Group. This makes it obvious that safety of passengers is not ensured, for even a minor miscalculation or mix-up can lead to a breakdown in the system, says an article in Guangzhou Daily. Excerpts:

Surprisingly, the subway train ran in the opposite direction without meeting with an accident. However, the incident should not be understated and the authorities should take measures to prevent recurrence of such weird situations. The passengers were lucky this time, but they may not always be.