The rocks hit the group of travellers as they waited to board boats in the Diecai Mountain scenic area in Guilin, China Radio International (CRI) said.
Pictures posted online showed rocks -- one as big as a metre (three feet) wide -- resting on broken pavement splattered with pools of blood with handbags, shoes and other personal items scattered across the ground.
"Four were killed at the scene and four others injured," CRI said in a report on its website. "Three of the injured later died in hospital."
Xinhua said the fatalities were the result of a "huge boulder", while CRI and state broadcaster China Central Television (CCTV) said "rocks" fell down the mountain.
CCTV said in a Tweet that 19 people were injured, with eight of the casualties from Taiwan.
The area is known for its karst mountains and caves, and is a popular site for Chinese and foreign visitors, with Diecai Mountain -- also known as Folded Brocade Hill -- offering stunning views.