A blast at a coalmine in Colombia has killed 16 miners and left about 70 trapped underground, officials say.
The explosion happened late on Wednesday at the San Fernando mine in Amaga, Antioquia province.
Officials say there is little likelihood of finding survivors as rescuers tried to get into the mine.
"To be honest there is not much [hope], very little, practically none," Luz Amanda Pulido, a national disaster official, told local radio.
The blast happened at 2200 local time on Wednesday when miners were changing shift, officials said.
For that reason, the exact number of people inside the mine was unclear, they said.
Rescuers were trying again to get inside the shaft on Thursday morning.
It is not yet clear what caused the blast but officials said there may have been a build-up of gases. There are fears the death toll could rise further.
President Alvaro Uribe described the disaster as "a huge tragedy" and said "my heart goes out" to the families of the dead.
Colombia is one of the world's largest coal exporters.
It has the second-largest reserves in South America, after Brazil. According to the US Energy Information Administration, it was the fourth largest coal exporter in the world in 2008.
Dozens of workers have been killed in explosions at mines, many of which are makeshift.
A methane gas explosion killed eight workers in a mine last year, also in Antioquia province.
In February 2007, a gas explosion at a mine in north-eastern Colombia killed more than 30 workers.
After the blast at the makeshift La Preciosa site, about 580km (360 miles) north of the capital, Bogota, authorities said they would step up their supervision of Colombia's mines.