Six migrant workers were suspected of suffering from pneumoconiosis, an occupational lung disease, after getting a diagnosis from a government-designated hospital on Monday, local authorities said Tuesday.

A total of 26 migrant workers had medical check-up at Shenzhen Occupational Disease Control and Prevention Hospital Monday, a municipal petition office spokesman said.

Six were suspected of having the pneumoconiosis, a restrictive lung disease caused by the inhalation of dust. Six were found to have shadows in the lung and four had tuberculosis. The rest of them were healthy, he said.

They could use the check-up results to take further actions, he said.

A total of 119 migrant workers engaging in the air blast drilling in the booming southern city had petitioned in several government departments since September, claiming they had suffered from pneumoconiosis because the companies they worked for did not provide qualified prevention facilities.

They were all from Zhangjiajie City in central China's Hunan Province.

They need to get an occupational disease diagnosis from government-designated hospitals in order to get compensation from their employer but they were refused by some hospitals as they could not provide their labor contracts.

The 26 migrants workers were confirmed by the authorities to have work relations with their employers, who have to compensate the workers if they were confirmed to have the pneumoconiosis.

A Shenzhen Labor Supervision Team official said 33 of the 119 migrants had social insurance records, 10 with work permits and 76 had no certificates.