Updated

SAN JUAN DE SABINAS, Mexico -- A gas explosion Tuesday in a coal mine trapped 14 miners and injured another in northern Coahuila state near the U.S. border.

A mine employee wearing a mask and air tank was lowered into the shaft to evaluate conditions for a possible rescue at the small mine, and emergency personal and federal and state officials gather outside the pit head.

There were no confirmed deaths and as of Tuesday afternoon rescue crews had yet to reach the trapped miners, said Luis Martinez, mayor of the town of San Juan de Sabinas, Mexico, where the mine is located, about 85 miles southwest of Eagle Pass, Texas.

The 14 miners had gone down the 197-feet deep shaft when the explosion happened early Tuesday. The had opened just over a month ago, and employed a total of about 25 miners.

The national mine workers' union said in a statement that the mine's work force was not unionized, and it criticized what it called "the totally unsafe conditions in which coal mines in Mexico, and especially in this region known as the coal belt, operate."

The injured miner, 15, had been working on a conveyor belt separating coal from tailings when the blast occurred in the early morning hours.

He was taken to a hospital in serious condition, said Jesus Espinoza, a spokesman for mining company BIMSA.

Federal prosecutors late said both his arms had been amputated and that he remained in serious condition.

Officials said they were investigating who was actually operating the mine, because there was conflicting registry data.

And the federal Attorney General's Office said it had opened an investigation in to the blast, which it said was caused by a gas buildup.

A similar blast caused by methane gas killed 65 miners in February 2006 at the Pasta de Conchos coal mine in San Juan de Sabinas, near where Tuesday's explosion occurred.

Rescuers eventually recovered the bodies of two miners from the 2006 blast but tons of wood, rock and metal, as well as toxic gas, prevented the recovery of the others.

Still smarting from criticism about the government's failings in mine safety, and their inability to recover the bodies from the 2006 blast, federal officials promised aid to the trapped miners' families and all necessary assistance in the rescue effort.