The U.S. Department of Labor on Wednesday took the unprecedented step of going to federal court to close down a Kentucky coal mine owned by Massey Energy Co., and promised similar action involving other mines deemed dangerous to miners.

Solicitor of Labor Patricia Smith told reporters that sections of the Freedom Energy Mine No. 1 in Pike County, Ky., have been shut down for safety violations 55 times this year. Wednesday's request for an injunction in U.S. District Court would close the entire mine until all violations were corrected and a safety plan was drafted.

"Given what we've seen in the last two months, we feel that it's not just a maintenance issue," Ms. Smith said. "This mine is one accident away from a possible tragedy."

Freedom Energy No. 1 is an old, medium-sized mine with extensive underground workings. It employs 135 miners, 35 to 50 of whom may be underground at any one time.

The Labor Department's Mine Safety and Health Administration has reported long-term problems in the mine's structure, ventilation and maintenance.

MSHA has been focusing on dangerous mines since April 5, when an explosion in Massey's Upper Big Branch mine in West Virginia killed 29 miners, the deadliest blast in a U.S. coal mine in 40 years.

Massey, which is headquartered in Richmond, Va., and operates mines in Kentucky, Virginia and West Virginia, has 21 days to respond to the lawsuit.

A Massey spokesman Wednesday said company Chairman and CEO Don Blankenship visited the mine last week and does not consider it unsafe. But because of its age and size, the company is considering idling it until it can meet MSHA standards.

The corrections could be made in a matter of weeks, Ms. Smith said, if the company cooperates.

Ms. Smith said MSHA turned to the court system because it cannot order the entire mine closed and it cannot direct the mine to continue to pay its employees for more than one week.

"The court has the discretion to order remedies a government agency cannot demand," she said.

Another Massey mine also was being considered for court action, Ms. Smith said, but the mine operator already has closed it.

"MSHA is going to continue doing what it can under the law," Ms. Smith said. "And this is an example of it looking at all the tools that are available to it. We will continue to do this until it is determined that miners are safe."

While the hazards and safety violations were cited in the MSHA filing, Ms. Smith said the agency also was aware of the mine's injury rate.

"My understanding is that Massey underreports injury rates to its shareholders by 37 percent," she said. "[The injury rate] has been average, but it has been going up."

Still, she said, MSHA is not targeting Massey and a number of other mining operations across the country are being closely watched for similar court action.

"You can expect more of these on other mines," she said.