UPSHUR, the United States, Jan. 5 (Xinhuanet) -- An eastern U.S. coal mine, where an underground explosion killed 12 miners this week, has been cited for hundreds of federal safety violations since it opened in 1999, U.S. media reported Thursday.

    Among the infractions were at least 16 related to failures to prevent or adequately monitor the buildup of explosive gases in the Sago Mine, Upshur County, West Virginia.

    Although the bodies of the 12 miners were removed from the mine Wednesday, U.S. authorities are yet to determine the cause of the explosion that trapped the miners Monday.

    Meanwhile, government records show that the Sago Mine has been cited repeatedly for not having an adequate ventilation plan and for violating rules requiring safety inspections before each eight-hour shift.

    The number of infractions issued to the mine last year was higher than would be normally issued to a mine that size, according to data from the U.S. Mine Safety and Health Administration (MSHA).

    Since 2000, the incidence of injuries at Sago was also higher than average -- more than twice the national rate.

    In 2005, the mine was cited for nine times for failing to properly enact a "mine ventilation plan," with three of those violations considered by the MSHA as "significant and substantial."

    Also, the mine was cited for seven times last year for failing to properly conduct a "pre-shift examination," the safety inspection mandated before each shift of workers is allowed to enter the mine.

    Moreover, the mine had extensive safety problems that led the agency to close parts of it 18 times last year.

    In all, the Sago Mine received 276 violations in 2004 and 2005, including 120 that were considered "significant and substantial."

    During that time, the government sought 33,600 U.S. dollars in fines and the mine's owner paid 23,986 dollars.

    Compared with three other similar-sized mines in West Virginia, the Sago Mine had far more violations during that period.

    In the United States, coal mine fatalities have dropped dramatically over the past century from a high of 3,242 in 1907 toa record low 22 in 2005, MSHA records show.

    The coal industry also has shrunk to just more than 100,000 workers, but the fatality rate today is a fraction of what it was at the industry's peak of 863,000 workers in 1923.

    The injury rate in the coal-mining industry was barely above the national workplace injury rate in 2004, the most recent year for which Labor Department data are available.

    Coal-mine employees suffered 5.6 work-related injuries or illnesses per 100 employees, compared with 4.8 injuries and illnesses for the entire private-sector workforce. Enditem