A wage dispute in southern Guangdong Province turned violent as hundreds of migrant workers allegedly clashed with riot police, smashed cars and indiscriminately attacked passersby.

The authority said on Tuesday nine people allegedly involved in a violent wage-related dispute in southern Guangdong Province have been detained.

More than 200 migrant workers, natives of Sichuan Province, gathered on Monday night in front of a government building in Guxiang township of Chaozhou, Guangdong Province, protesting a wage-related dispute that has already led to the serious injury of a migrant worker, Xinhua reported.

Protesters smashed three cars and burnt another vehicle during the unrest on Monday night. Nine of them were arrested before they were dispersed by 10:30 pm, local police said.

Police did not disclose if there were any casualties in the incident.

According to an online statement said by Chaozhou Public Security Department, the violence was caused by the serious injury of a migrant worker, surnamed Xiong, from Deyang city of Sichuan, who works for a local ceramics factory.

Xiong, 19, was seriously wounded in a knife attack after he argued with the factory boss for owed wages at the workshop on June 1. Xiong's father suffered a head wound in the conflict, Yangcheng Evening News reported.

The boss of the factory, surnamed Su, surrendered himself to local police on Saturday and confessed his crime, while the other two suspects in the attack were also seized Sunday, police said.

After the incident, the Guangdong provincial public security department ordered local police authorities to carry out a full investigation into the case, calling for better protection of migrant workers' rights.

Deng Jianhua, deputy director of the information office of Sichuan's Deyang city, asked for an open and thorough investigation into the violence.

"We are doing what we can to protect the rights of migrant workers from Sichuan. Please be assured that we will try our best," he wrote on his micro blog on Tuesday.

"But authorities in Chaozhou should make public why workers from Sichuan were so angry and took such an extreme action to protect their rights," he added.

China has witnessed a rise in the number of labor disputes in recent years, especially in regions such as Guangdong, which is clustered with labor-intensive industries.