Qingdao city government will launch a safety and quality inspection campaign of all its subway construction projects after two metro lines were hit recently by accidents and claims of substandard work.
All other major construction projects in the seaport city in Shandong province will also be inspected.
Authorities have set up three investigation teams since June 28 to screen all construction projects, including the labor subcontracts.
The inspections are focusing on risks related to improper construction methods, poor management and geological weaknesses.
A worker died last Thursday after a building collapsed at a construction site on the No 1 metro line, creating a 10-meter wide hole that the worker fell into.
On May 27, five workers were trapped and later lost their lives after another collapse at a construction site on the No 4 metro line.
A former contractor involved in work on the power supply for the metro project told local media last month that construction work was substandard and potentially hazardous.
The revelation led to the suspension of the general manager of the No 1 line.
Qingdao Vice-Mayor Liu Jianjun said the government was placing great importance on the investigation and had invited an academician to join the team to improve its professionalism.
"Besides that, we have garnered joint support from the departments of discipline inspection, public security, the procuratorate, the courts and the housing and urban-rural development authorities, as well as lawyers," Liu said in an interview with Dazhong Daily. "The investigation and inspection will be serious and thorough."
Zhang Jiangang, director of the Qingdao Emergency Management Bureau, said efforts were being made to ensure the ongoing investigations are conducted openly.
On Wednesday, Xinhua News Agency called for the Qingdao metro project to be open to close scrutiny.
The agency said there were a number of "thought-provoking questions" relating to potential safety hazards, unlawful acts and the two accidents that occurred in such a short period of time, as well as the issue of safety supervision from different parties including investors, builders and supervisors.
The Qingdao metro has four lines in service and is constructing another five to extend the network.
The No 1 line under construction is a major transport artery linking downtown Qingdao to Huangdao district with a tunnel section under the sea.
The No 4 line will link downtown Qingdao from west to east, passing through the European-style Shinan district to the newly developed Laoshan district.
