Mexico City (CNN) -- Experts from Chile who helped rescue miners there last October were heading Wednesday to northern Mexico, where nine workers remained trapped in a mine after an explosion, officials said.
Five Chilean specialists were expected to join rescuers at the mine by early Thursday morning, Mexico's foreign ministry said in a statement.
At least two of them "participated actively" in the rescue of 33 miners who were trapped for more than three months in a Chilean mine, Mexico's state-run Notimex news agency reported.
A blast Tuesday morning at mine just outside Sabinas, Mexico, left 14 workers trapped inside. Search teams pulled out five lifeless bodies late Tuesday and early Wednesday, Mexico's labor secretary said in posts on his Twitter account.
Rescuers continued to look for the nine remaining miners. But in one Twitter post, Mexican Labor Secretary Javier Lozano Alarcon described the prognosis as "not at all encouraging."
Authorities waited until toxic gases dissipated enough to allow rescuers to begin exploring the mine's tunnels, the state-run Notimex news agency reported.
A 15-year-old worker had both arms amputated after he was seriously injured in the blast, Mexico's attorney general's office said.
Lozano took a critical tone in a Twitter post as rescue operations began, saying "having a minor working here" was a "fault of the owner of this 'mine.'"
The mine had only been operating for 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 Mexico's attorney general's office said.
Federal authorities said they had no record of the company, and that the owners of the land where the mine is located never registered any excavation at the site, said Ricardo Rojo, a spokesman for Mexico's economic ministry.
But a Binsa spokesman rejected government claims the the company was operating in an irregular manner.
"It is one of the companies with the best safety," spokesman Jesus Espinosa said in an interview with Mexico's W Radio, adding that government and union officials had reviewed its operations.
The mine contains a shaft that is 60 meters (197 feet) deep, Sabinas Mayor Jesus Montemayor Garza said.
Federal authorities are investigating what caused the explosion while family members anxiously wait outside the mine and local workers from other mines help with the search.
"They are miners from Sabinas who are risking their lives in order to pull out the bodies of their peers," Montemayor 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 to 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.
CNN's Rey Rodriguez, Rafael Romo and Catherine E. Shoichet and journaists Hanako Taniguchi and Tania L. Montalvo of CNNMexico.com contributed to this report.