One of the four miners is lifted out of the collapsed gypsum mine after being trapped for 36 days. [Photo by Yu Peng for China Daily]

He also said the city will organize professional teams to repair more than 1 million square meters of land affected by mining to prevent collapses from happening.

The four miners were in stable condition after being transferred from intensive care wards to regular wards on Sunday, China Central Television reported.

Wu Dawei, an intensive care unit doctor at Shan-dong University’s Qilu Hospital, said the four miners must remain under observation after being underground for so long.

Guan Guozhong, the son of Guan Qingji, one of the four workers rescued, said the past month had been “torture” for his family.

With rescue work and an investigation continuing, farmland at the rescue site and in nearby villages is still subsiding. In some areas, the land has subsided by several meters.

Deep cracks can be seen on roads and some houses near the site, while a hole several meters in diameter and about 10 meters deep lies on farmland nearby.

“The land has subsided so much,” one villager said. “I think the government will have to repair it so we can grow crops on the land again.”

Gypsum mining has been an important source of income for Wanzhuang, a village near the scene of the collapse, according to a report in Jinan Times, a local newspaper.

Contact the writers at wangxiaodong@chinadaily.com.cn