A car bomb went off outside a home in the village of Litianshang at about 1:50 p.m. Wednesday, killing five people at the scene, Xinhua reported.
Two other victims died at a local hospital Thursday. Eighteen other villagers were injured, including five who are in intensive care.
Liu Benquan, chief of the district's public security bureau, said a man named Chen, who is in his 50s, is the main suspect in the case. Chen is one of those in intensive care. He allegedly told police that he had driven the car to the scene and deliberately set off homemade explosives, Liu said.
The explosion happened outside of the home of a woman who divorced Chen, Liu said.