Rescuers trying to free 65 trapped in Mexican mine

Rescue workers were today burrowing through debris clogging a Mexican coal mine in a desperate effort to free 65 miners who had been trapped for more than a day by a gas explosion.

The miners were carrying only six hours of oxygen with them when the explosion occurred early yesterday, and officials said it was unclear if they had access to fresh air.

Rescue teams had failed to make any contact with those trapped at the mine near the town of San Juan de Sabinas, 85 miles south-west of Eagle Pass, Texas.

Several other workers who were near the mine's entrance at the time of the explosion were treated for broken bones and burns.

Rescue teams worked round-the-clock as family members waited for news, huddled near bonfires and wrapped in blankets to protect against the bitter cold. Officials had promised a pre-dawn briefing, but they had yet to appear and were not letting anyone in the security zone.

Sergio Robles, director of Coahuila state's emergency services, said the miners were carrying six hours of oxygen with them and were located up to three miles from the mine's entrance.

He said rescue officials had advanced up to 300 yards into the mine after working nearly 20 hours. It was unclear when they would reach the miners. The explosion occurred around 2.30am local time (0830 GMT) yesterday.

Rescue efforts were slowed by the presence of toxic gases, including carbon monoxide, Robles said. When asked if officials believed the miners survived the explosion, Robles said: "It would be difficult because of the presence of gas. But we are holding out hope of finding someone alive."

Juan Rebolledo, vice president of international affairs for mining giant Grupo Mexico, which owns the mine, said oxygen tanks were scattered throughout the site, but it was impossible to know if the trapped miners had access to any of them.

Coahuila Gov. Humberto Moreira Valdes, who was at the site overseeing the rescue operation, told Televisa network that the mine's ventilation system was still working.

Rebolledo said several rescue teams were taking turns carefully removing debris that had clogged the steep shaft.

"It's slow work because of the quantity of debris," he said.

Officials had cordoned off the area, and worried family members waited outside the security zone for information.

As well as mining coal, Grupo Mexico is the world's third-largest copper producer, with operations in Mexico, Peru and the United States.

There have been various fatal mining accidents in Coahuila. The worst was in 1969 when more than 153 miners were killed in a pit at the village of Barroteran. In 2001, another 12 people died in an accident at a mine near Barroteran.

Last month, 14 miners died in two separate accidents at mines in West Virginia, in the United States. Two men died in a fire January 21 at a mine in Melville, nearly three weeks after 12 men died after an explosion near Tallmansville.

In Canada last month, 72 potash miners walked away from an underground fire and toxic smoke after being locked down overnight in airtight chambers packed with enough oxygen, food and water for several days.