Authorities in south China's Guangdong Province have arrested 29 employers who had been wanted for defaulting on wages due to migrant workers in the past 20 months.

The authorities recovered 46.71 million yuan (6.45 million U.S. dollars) for the workers who left poor rural area to work in cities, said Liu Youjun, Communist Party of China chief of the Guangdong department of labor and social security.

Reporting to a State Council inspection team on migrant workers' conditions, liu said his department began to cooperate with justice authorities in April 2006 in dealing with cases of unpaid wages and had since reported 231 cases to the police.

The provincial government had also named and shamed 107 enterprises that had defaulted on wages since 2006, which Liu said was a serious warning to all employers.

The number of major default cases -- those involving at least 30 migrant workers -- last year dropped 14.2 percent year-on-year, said Liu without giving details.

China has more than 120 million migrant workers including 26.2 million in Guangdong. They travel to the cities to work in construction, mining, cleaning and catering industries, the kind of jobs usually labeled "dirty", "heavy", "hard" and "exhausting".

News reports have frequently exposed infringements of their rights, such as unpaid wages and poor accommodation.

The central government has attempted to improve their welfare in recent years. China's top legislature, the National People's Congress, adopted a resolution last March, providing for rural migrant worker representatives in the national parliament for this year's full session.