BEIJING, March 30 (Xinhua) -- Rescuers recovered a worker's body from a collapsed subway tunnel in Beijing Friday afternoon after more than 50 hours of excavation, but five others are still buried underground.

    The body was found at about 6:40 p.m. at a construction site for the No. 10 Subway Line in Haidian Nanlu Road between the third and fourth northern ring roads in the city's Haidian District.

    Rescuers are still trying to reach five other workers buried underground since 9:20 a.m. Wednesday, but they held out little hope that they could have survived.

    The collapsed section of the tunnel covers an area of about 20 square meters and is about 11 meters underground.

    Local police have detained 10 people over the subway cave-in, including the work supervisor and tunnel designers but the labor contractor, Zhou Yongfu, is reported to have fled.

    The construction company -- China Railway 12th Bureau Group Co.-- refused to report the accident to municipal authorities when the collapse occurred, instead mounting its own operation to rescue the trapped workers.

    In an attempted cover-up, project managers ordered all the workers to stay at the construction site and told them not to talkto media and police. They confiscated mobile phones from workers.

    The Beijing municipal authority finally learned of the accident at 5:00 p.m. on Wednesday, almost eight hours after the collapse occurred, after a worker from Henan called Henan police.

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