The explosions took place in front of the office building of the Shanxi Provincial Committee of the CPCC in Taiyuan, the provincial capital, state-run Xinhua news agency reported.
Among the eight injured, one was seriously wounded.
Eyewitnesses said the blasts were caused by explosives placed on a minivan.
A big explosion was heard and heavy smoke and flames were seen, said Liu Guoliang, an eyewitness who was driving from west to east on the Yingze overpass.
Liu saw a minivan blasted with heavy smoke and spread a lot of debris at the scene when he waited for traffic lights in front of the office building, Xinhua said.
The accident is suspected to be caused by self-made bombs as steel beads were scattered at the scene, the report said.
The site of accident has been cordoned. Police are investigating the case.
The blasts followed October 28 suspected suicide attack at the Tiananmen square here in which five persons including three suicide attackers from China's Muslim Uyghur Xinijiang province were killed and 40 others injured.
Chinese police said the attack in which three members of a family drove a SUV vehicle to the highly guarded entrance of the Forbidden city in Tiananmen square was caused by East Turkistan Islamic Movement, an al-Qaeda affiliate fighting for the independent Xinjinag.
It is not yet clear whether today's explosions were in any way related to that.