URUMQI - Police had arrested a farmer who is suspected of having killed five people in northwest China's Xinjiang Uygur Autonomous Region, local police authorities said Thursday.

The 27-year-old male suspect killed five people and injured seven others outside a supermarket in Korla city around 3 p.m. on March 7, according to police investigation.

Police discovered that the suspect, a farmer from Hejing county, was addicted to gambling and had long time bad relationship with his family. The suspect committed the murder to take revenge on society after a quarrel with his family members.

The suspect had been punished three time for stabbing, according to police records.