BEIJING, March 30 (Xinhua) -- Beijing police have detained 10 people after a subway tunnel collapsed on Wednesday morning trapping six workers.

    Rescue work was still underway at the Haidian district of Beijing, but rescue officials held out little hope that the workers could be able to survive the accident.

    Those detained include the supervisor and the designers of the tunnel but the labor contractor, Zhou Yongfu, has disappeared, the Beijing Times reports on Friday.

    The collapse occurred at 9:20 a.m. Wednesday, but the construction company -- China Railway 12th Bureau Group Co. -- failed to report the accident to municipal authorities and instead tried to rescue the trapped workers on its own.

    The management of the project ordered all the workers to stay at the construction site and told them not to talk to media and police. They confiscated mobile phones from workers.

    The Beijing municipal authority apparently learned of the accident at 5:00 p.m. on Wednesday, almost eight hours after the accident occurred, from an unidentified source.

    Workers' anger was palpable. Signs showing the construction company's logo were defaced at the construction site.

    The collapsed section on the new No. 10 subway line covers an area of about 20 square meters and is about 11 meters underground, rescuers said.

    Beijing officials on Friday told Xinhua that rescue work had been delayed by the company's cover-up attempts and the complicated underground conditions.