Mexico City (CNN) -- Rescuers overnight recovered four bodies from a coal mine in northern Mexico that suffered an explosion last week, making a total of 11 bodies that have been extracted so far, the country's labor secretary said Saturday.
Javier Lozano says at this point -- more than four days after the blast -- there is no hope of finding alive the remaining miners trapped inside.
Three more miners remain inside the shaft.
The mine had been operating for only 20 days and had 25 workers who were not unionized, Lozano said.
He described such small, makeshift coal mines as "unsafe places," calling them "irregular, deadly traps, as we are seeing."
The owner of the mine is a company known as Binsa, the statement from the attorney general's office said.
The mine contains a shaft that is 60 meters (197 feet) deep, Sabinas Mayor Jesus Montemayor Garza said.
Sabinas is in the coal production center of Mexico and has a museum dedicated to the history of coal mining.
Several chapters of that history, however, have been tragic.
In 2006, in the nearby town of San Juan de Sabinas, 65 miners perished after an explosion in the mine where they were working. Explosive gas inside the mine hindered the rescue of the miners at the Pasta de Conchos mine, which the government eventually abandoned.
An organization representing family members of the victims of that accident said Tuesday's blast was a tragic reminder that the federal government must do more to regulate mines. One activist from the organization said there had been more than 40 people killed in local coal mines since the 2006 accident.
"How long will it take to recognize that there is a very serious crisis in coal mining (in the Mexican state of) Coahuila, in which the workers and their families are those who must endure the worst, with dead, widows and orphans?" a statement from the organization said.