HUNTINGTON, Utah (AP) – Six miners were trapped in a cave-in Monday at a coal mine less than 20 miles from the epicenter of a minor earthquake, authorities said.

The Genwal mine reported a “cave-in” at 3:50 a.m., an hour after the magnitude 4.0 earthquake, the Emery County sheriff’s office said. “Rescue workers are on scene trying to locate six miners that are unaccounted for,” the sheriff’s office.

There had been no contact with them, said Dirk Philpot, a spokesman at the Mine Safety and Health Administration in Washington.

The miners were believed to be 1,500 feet below the surface, about four miles from the mine entrance, Philpot said.

Rescuers were within 2,500 feet of their presumed location, he said. He had no details on the difficulty of the search.

Walter Arabasz, the head of the University of Utah’s Seismograph Stations, said there was a clear link between the quake and the mine collapse, based on wavelengths.

A command center was being set up in Huntington, about 15 miles from the mine, said Teresa Behunin, an accountant with Utah American Energy, which owns the mine. She had no other details.

Rocky Mountain Power, a utility with a power plant in the area, sent a rescue team and heavy equipment to the mine, about 140 miles south of Salt Lake City, spokesman Dave Eskelsen said.

The sheriff’s office had said earlier there were no reports of damage or injuries blamed on the quake, centered under the Huntington Canyon area.

“We aren’t panicked yet,” Linda Jewkes, president of the Emery County Chamber of Commerce, said after hearing the news. “We’re very, very concerned and very cautious when it comes to the mines.”

Utah ranked 12th in coal production in 2006. It had 13 underground coal mines in 2005, the most recent statistics available, according to the Utah Geological Survey.

Emery County, the state’s No. 2 coal-producer, also was the site of a fire that killed 27 people in the Wilburg mine in December 1984.