Mine manager Ruben Escudero "informed us that all the miners are dead. There is nothing that can be done," Juan Hernandez, the nephew of one of the trapped men, said on Saturday.
The Grupo Mexico company said that while no bodies had yet been found, tests showed there was almost no oxygen inside the mine's shafts and tunnels and no hope of finding survivors from the last Sunday explosion.
Xavier Garcia, a senior executive at Grupo Mexico, said: "We are moving on to the hard task of the physical recovery of our miners so the families can start their mourning."
The pre-dawn explosion of methane gas and coal dust tore throughout the the Pasta de Conchos mine in Mexico's northern state of Coahuila, trapping the 65 night shift workers, some of them almost 2.5km underground.
The blast sent temperatures soaring above 600 degrees Celsius and filled mine shafts and tunnels with methane and carbon monoxide as well as collapsed rock.
"These conditions made survival impossible," said Garcia, who appeared close to tears.
Relatives who held an emotional vigil at the mine gates since last Sunday wept and hugged each other after being told there was no chance their men would be rescued alive.
Red Cross officials treated 10 people suffering from emotional distress.
Some families quickly packed up their things and went home, while others accused company officials of negligence and deceiving the families with talk of possible rescues earlier in the week.
Aida Farias, whose husband, Elias Valero, was one of the men stranded deep in the mine's tunnels, said:"They tricked us because they knew from the beginning how the mine was, they played with us like puppets.
"I will be here until they give me my husband's body and they have to give it to me," she said.
Rescue teams spent several days digging desperately around the clock at huge piles of rock and dirt, hoping to find a way through to the trapped men.
They pulled out hundreds of tonnes of rubble, but the search was suspended on Friday night because high levels of methane gas threatened of a new explosion.
No contact was made all the week with any of the missing men, who were stranded with only a few hours worth of oxygen in their gas tanks and little or no food and water.
Their only chance of survival had been if they were close to a large pocket of clean air, or if ventilator shafts were pushing enough clean air into their area of the mine.
A team of US experts helped to carry out the tests that demonstrated that the quality of the air was so bad throughout the mine that no one could have survived.
Relatives exploded in anger and roughed up Labour Minister Francisco Salazar after they were told the search was being suspended on Friday. Some complained rescuers were not given sophisticated heat-seeking equipment to locate the miners.
Grupo Mexico has said it will pay compensation of about $70,000 for each of the men killed and almost $10,000 for each of the 13 men who were injured in the blast but not trapped.
Reluctant to promise
Efforts to recover the bodies will begin as soon as experts clear the mine of the lethal levels of methane gas, most probably in the next two or three days.
Officials were however reluctant to promise they would be able to find all the dead.
"It depends on the mine's conditions," Garcia said. "We are going to put all our efforts into it."
Union leaders say Grupo Mexico ignored safety concerns, but the company has denied negligence and said a recent government check on conditions at the mine concluded it was safe.
Salazar said an investigation was under way and that Grupo Mexico would face sanctions if it was found to be responsible for the disaster.
About 450 men worked in the mine for salaries of between $250 and $500 a month. It might now be closed for good.
Rescue teams have suspended the search for 65 men trapped for the past six days in a Mexican coal mine because of safety concerns.
Arturo Bermea, a senior executive at mine owner Grupo Mexico, told weeping relatives the search was on hold for two to three days because of the risk of further explosions in the mine's tunnels.
Dozens of rescue personnel have worked around the clock, digging with spades and their bare hands after last Sunday's explosion trapped the 65 men deep in the Pasta de Conchos mine in Mexico's northern state of Coahuila.
Rescuers already have said at least half of the missing men probably were dead because there was not enough oxygen in their sections of the mine at the time of the explosion.
Most of the relatives who have waited at the mine's gates for days on end for word of their missing men broke down in tears, and army troops had to hold some of them back as they tried to surge through the entrance.
Bermea said experts would spend the next two or three days drilling into the mine from the surface to create holes and suck out the methane gas, which mine officials say is lethal when it rises to above 15% of the atmosphere.
He said: "We have always believed there is hope that the workers are alive and we will continue working indefinitely."
Many rescuers and relatives were close to giving up hope on Friday.
Francisco Salazar, Mexico's labour minister said as many as 25 miners probably had died in one section of the mine.
Search teams have struggled to dig through hundreds of tonnes of rubble to reach the men, while relatives held a vigil at the mine entrance. So far, no bodies have been found and no contact has been made with the trapped men.