The federal government has cited three Kentucky coal companies for mine safety violations in its latest round of impact inspections.

The Mine Safety and Health Administration began conducting surprise inspections of coal mines nearly six years ago, after 29 workers were killed in a West Virginia coal mine explosion. The agency targets mines with a history of safety and compliance problems for its monthly impact inspections. The mines cited last month are in Pike, Bell and Muhlenberg counties.

Coal mine fatalities were at a record low in 2015, with only 11 miners killed on the job. But 2016 might not fare as well; in the first three weeks of 2016, three coal miners were killed. One of those was in Webster County, Kentucky.