Police in Guangdong province are offering a reward of 100,000 yuan ($15,000) for the capture of the suspect in a mass shooting on Tuesday nightin Raoping county.

Lin Zhonghong, 40, is accused of killing three people and injuring six others in Raoping county, according to the local public security bureau.

According to a witness, Lin opened fire on two brothers, Lin Zhenxiao, 49, and Lin Zhentian, 47, in Jingzhou township at 7:53 pm, killing both.

The brothers threatened to beat the suspect with steel pipes because he had attacked them the previous night, according to a source close to the case who did not want to be named.

Previously, Lin Zhonghong, the suspected shooter, had a fierce quarrel with the brothers after failing to reach an agreement on opening secret casinos, the source said.

After shooting the brothers and fleeing, Lin opened fire on people who were chasing him.

Police were immediately sent to the scene and found the two brothers dead. Both had been shot in the head.

Lin Zhikai, 20, the son of one of the brothers, Lin Zhentian, was seriously wounded and died later at the hospital.

The six who were injured, including a 13-year-old boy, are males and residents of Jingzhou. The oldest person wounded was Lin Yuxi, 55.

According to a statement from the Raoping public security bureau, the police are going all-out to hunt down the suspect and urged residents and witnesses to tip off the police as to the suspect's whereabouts.

Police said they would not reveal the identity of anyone who provides information.

A task force has been set up to investigate the case, the statement said.

Cai Yanhuan contributed to this story.