A year on families are still mourning victims of the mine explosion

Relatives staged a vigil at the mine in Coahuila state, reading the names of the dead and releasing white balloons at the exact time of the explosion.

Work is continuing to retrieve 63 bodies trapped below but the families are angry at the lack of progress.

The mine's owners have always denied that safety precautions were ignored.

On 19 February last year, an underground blast brought down thousands of tonnes of rock at the Pasta de Conchos mine near the town of San Juan de Sabinas, 100km (60 miles) from the US border.

Families had to endure several days' wait before the search for 65 men working underground was called off amid security concerns.

Since then, recovery operations have been hampered by fears that explosive gases could be ignited inside the mine.

"I want my husband in a grave where I can go to pray and bring him flowers," mourner Maria Aguilar told the Associated Press.

During the ceremony, about 100 relatives and friends read out the names of the dead.

Strike call

Police stood by ready to counter any unrest among the families who are angered by the failure to locate more than two bodies and what they see as the lack of legal action.

Miners' unions were planning to hold a one-day strike across Mexico on Monday to call for Grupo Mexico, the country's biggest mining company, to be brought to account, Reuters reported.

Officials have so far not determined the cause of the blast but investigators found problems with the ventilation system in the mine and believe there was a deadly mix of methane, heat and oxygen.

A special prosecutor is calling for 11 mine officials and government inspectors to face manslaughter charges.

Grupo Mexico has said the explosion was an accident and that safety standards were met.

The company has paid $75,000 (�38,000) compensation to each of the miners' families.