Federal inspectors issued 35 citations and orders during so-called "impact" inspections at Kentucky coal mines in July, according to the U.S. Mine Safety and Health Administration.
The agency started the special inspections in 2010 to give increased attention to mines where there was a concern over poor compliance histories or other problems.
MSHA chief Joe Main said in a news release that the program has boosted mine safety.
As of June, the number of violations found for each hour of inspection time was down 19 percent, and serious violations were down 27 percent, Main said.
MSHA said the Kentucky mines that received citations or orders in July were New Jet LLC's Eagle 3 underground mine in Pike County; Appalachian Mining & Reclamation's Ivel preparation plant in Floyd County; Pine Branch Mining's Thunder Ridge surface mine in Leslie County; Alden Resources underground Mine #3 in Knox County; and The Paradise #9 underground mine in Muhlenberg County, operated by KenAmerican Resources.
MSHA has conducted 798 impact inspections, issuing nearly 14,000 citations and orders.
The agency started the program after Massey Energy's Upper Big Branch mine in West Virginia blew up in April 2010, killing 29 miners.