Five victims died on the spot while one died in hospital.
State-run Xinhua news agency said the multiple explosions were caused by 15 letter bombs.
The blasts were reported in several locations, including at a shopping mall, prison, a county government office, supermarket, transport station, hospital, animal husbandry, vegetable market and diseases control centre, Hong Kong-based South China Morning Post said quoting reports from the social media site Weibo.
The blasts occurred at the seat of Liucheng county and the surrounding areas, with the first heard at about 15:50.
Initial investigation showed that explosives could have been inside express delivery packages, Xinhua report said.