About 100 attackers, wielding machetes and sticks, beat up villagers who complained about land grabs in Yuanhe of Pizhou City last Thursday, the reports said.
Li Dongdong, 22, reportedly died from multiple stab wounds in his chest while another villager was badly injured with stab wounds to his stomach.
Photographs posted in the reports show hundreds of people protesting with banners on the streets of Pizhou against land grabs and killing by gangsters.
The Information Center for Human Rights and Democracy said some 50 other villagers were injured when 200 police officers clashed with hundreds of people who were carrying Li's body to protest at the municipal Communist Party office the next day.
The Hong Kong-based watchdog said police confiscated Li's body and dispersed the crowd. Police were patrolling major traffic routes and blocking news of the clash from being reported.
The reports said Yuanhe township officials sold 300 acres of farm land that belong to the people to Xuzhou Haitian Petrochemical Co. for 20 million yuan ($2.9 million) to build new plants.
Reports of sometimes fatal disputes over land sales between villagers and thugs allegedly hired by either land developers or government officials are commonplace amid the breakneck economic development in China in recent years.
==Kyodo