Thirty-nine Vietnamese illegally living and working in Anhui province have been transferred to border defense authorities, local authorities said Thursday.

Earlier this month police discovered the illegal migrants working at Xiecheng Metal Products Co., Ltd. in the city of Wuhu, said Hu Changyin, an officer in charge of foreign affairs with the city's public security bureau.

The 39, including two women, were introduced by a job agent to the company to manufacture molds, Hu said.

The public security bureau detained the Vietnamese, mostly born after 1990, and later transferred them to the Dongxing port border defense checkpoint in Guangxi Zhuang autonomous region that neighbors Vietnam, after reporting the case to the Exit-Entry Administration of the Ministry of Public Security, he said.

The company's chief executive has been detained by local police, he added.

In recent years, agents drawing labor from neighboring countries to work illegally in China has increased given the rising wages for locals, said Hu.

The illegal labor puts social stability at risk, he said.

A month ago, Vice Minister of Public Security Yang Huanning vowed to strengthen management of foreigners illegally entering, living or working in China while delivering a report on the administration of entry-exit, residence and employment of foreigners to the Standing Committee of the National People's Congress, the top legislature.

Yang said the crackdown will include improving the visa policy, strengthening border control, repatriating illegal aliens, and setting up repatriation locations in regions that have large numbers of such foreigners.

He said such foreigners, often from neighboring countries, mainly illegally worked in languages training, performance, housekeeping and labor-intensive industries.

The national capital of Beijing on May 15 launched a high-profile crackdown on foreigners illegally entering, residing or working in the city to maintain public safety.

The campaign, which will run until the end of August, will include household checks in Wangjing, Sanlitun and Wudaokou, areas of the city known for their high concentration of foreign residents, as well as on-the-spot street checks that will require foreigners to present valid identification.

Beijing police have also opened a tip hotline and will tighten reviews of visa applications during the period.