Authorities in northern China have arrested five people accused of starving and beating workers at a brick kiln to keep them enslaved, state media reported Monday.

The suspects were arrested for "illegally holding and deliberately injuring laborers ... and forcing them to do highly intensive manual labor," the official Xinhua News Agency said.

The five include the kiln boss, the foreman and three others, Xinhua said. It said police are looking for three more people in connection with the case, which has shocked China and exposed links between Communist Party officials and the kiln owners.

A man who answered the telephone at the Shanxi provincial public security bureau confirmed the arrests but would not give any details.

Heng Tinghan, the foreman, accused of using slave workers since March, was captured in central China's Hubei province Saturday night after a nationwide hunt.

Heng, 42, had become the chief suspect in the scandal after state media said a worker died at the kiln he oversaw, running photos of workers with their skin rubbed raw or severely burned.

Heng lured 31 rural laborers from railway stations of neighboring Henan and Shaanxi provinces, as well as Shanxi province, Xinhua said. He allegedly offered to help them find jobs then forced them to work in the brick kiln at Hongtong, a county in Shanxi.

Heng contracted the kiln from Wang Bingbing, the kiln boss, and the workers suffered harsh conditions, Xinhua said.

"The laborers were forced to work long hours on poor food. Dogs were hired to prevent them from escaping," the report said. "Many were burnt as they worked in the hot kiln."

On Sunday, Xinhua also said that another 20 slave laborers at brick kilns and other illegal workplaces in Shanxi had been freed, bringing the total of laborers released in Shanxi and Henan to 568.

More than 20,000 police were deployed in Shanxi alone to raid suspected illegal workplaces, with 168 people detained for running illegal kilns and mines there and in Henan.

The use of slave workers came under the spotlight in part because of an open letter posted online signed by a group of 400 fathers appealing for help in tracking missing sons they believed were sold to kiln bosses.

The fathers accused Henan and Shanxi authorities of ignoring them or even protecting the kilns and human traffickers, saying about 1,000 children were being forced to work at kilns under conditions of extreme cruelty.

Xinhua said Wang Dongji, a Communist Party branch secretary at a village in Shanxi, was being investigated after his son was found to be an owner of a kiln where 32 people were starved, beaten and forced to work 14 hours or more a day.