Two of the injured are in critical condition, the health bureau in Jingzhou City said in a press release.
Emergency treatment continued overnight, but doctors are uncertain if they will survive, it said.
Of the other six injured, the release said four are serious but stable.
The coach, owned by a transport company in Enshi, went through the guardrail of the Jingzhou Yangtze River Bridge and fell down. The vehicle had 36 seats and was carrying 22 people from the provincial capital Wuhan to Enshi.
Authorities are yet to identify the victims, most of whom were migrants.
Beijing: At least 14 people were killed and eight others injured after a double-decker sleeper coach plunged off a bridge on the Yangtze River in China's central Hubei Province, authorities said on Wednesday.
First Published: Wednesday, March 13, 2013, 13:46