The accidents occurred on Sunday afternoon on a river in Guizhou Province in southwestern China.
84 people ended up in the water and only four remained unharmed.
According to a preliminary investigation, the boats were not overloaded with passengers, reports the state TV channel CCTV.
China's President Xi Jinping urges "all possible efforts" in the rescue work and emphasizes the importance of strengthening safety routines at tourist attractions, according to the state news agency New China (Xinhua).
