About 50 rescuers were forced at times to use bare hands to try to open a narrow blocked passage in the mine near the community of San Juan De Sabinas.
Rescue operations moved slowly for fear of new explosions, officials said. "The 65 trapped people remain inside the mine," said Humberto Moreira, governor of the northern state of Coahuila.
More than 24 hours after the blast, over 200 distraught wives, children and parents of the missing workers maintained their vigil at the mine's entrance, desperate for word about the fate of their loved ones.
"They always said the mine was bad, (my husband) said that it smelled heavily of gas," said Vitela Norm, 53, as her daughter clung to her weeping.
Her husband, Jose Guzman Angel, is one of the 65 caught some 150 meters below the surface after the Pasta de Conchos mine, owned by
Industrial Minera Mexico, was blocked by an explosion on Sunday.
Mine telephones cut
Ten of the 87 people in the mine at the time escaped safely and 12 others were rescued suffering from serious injuries including burns. No word has been heard from the miners because the cave-in cut off the telephones inside.
"We do not know how they are, and we want immediate aid from everywhere," said Maria Gertrudis Hernandez, 50, whose husband was among the trapped miners.
Mr Moreira said rescue operations were going slowly because of the need to proceed with great care, owing to the risk of new explosions and cave-ins.
The explosion caused earth to crumble in a section of the pit, trapping the workers, Industrial Minera Mexico said in a statement.
"The situation is critical," a spokesman for public security in San Juan de Sabinas said by telephone, adding that dozens of troops, police and medical workers were supporting the rescue effort.
There was no official word on what caused the blast, but local media reports attributed it to dangerous levels of trapped, combustible gas.
It was not immediately clear if the trapped men were running out of air, as some authorities feared, or if the mine's ventilation system remained intact.
Mine company employees were using machinery to try to restore access to a shaft and get to the trapped miners, Formato 21 radio reported.
The workers were all on the mine's overnight shift. The mine itself is located just outside San Juan de Sabinas, home to some 40,000 people.
Series of irregularities
Ruben Escudero, an official of the Office of Labor and Social Safety in Coahuila, told reporters that an inspection of the mine on February 7 revealed "a series of irregularities".
One worker at Pasta de Conchos, who asked for anonymity out of fear of losing his job, told AFP that "things were very bad" in the mine. The man, whose brother-in-law was trapped below, said that miners had warned of increasing danger, but the company ignored them.
"Now they tell us that it was the workers' negligence, that they knew of the danger," said Mr Norm, whose husband worked at the mine for nine years for about US$70 a week.
Coahuila state, on Mexico's northern border with the United States, has about 95 percent of Mexico's coal reserves, and hundreds of miners have been killed in mining accidents in the area.
China has the world's most dangerous coal mining industry, official figures put the death toll last year at nearly 6,000, with 23 miners dying in one blast in the north earlier this month.
Seven miners were killed in an explosion in Romania a week ago and three in South Africa a few days earlier.
Early last month 12 men died in a mine in West Virginia in the United States.