The accident was caused by an underground explosion at the Upper Big Branch mine some 30 miles south of Charleston in the eastern US.
The blast happened around 3:00 p.m. said the mine's owner Massey Energy Company.
The number of fatalities makes this the worst US mine disaster since 1984. Rescue efforts have been suspended.
"We are sending all of our prayers and thoughts to the brave miners and their families," said West Virginia Senator Jay Rockefeller.
"I just spoke with President Obama and he has promised to make every asset available to help us and we will be in contact as the rescue continues," said West Virginia Governor Joe Manchin.
"We are all working diligently together and I ask that everyone pray for the miners, their families and our rescue teams."
Trapped teams
The blast happened as a number of workers were in a vehicle transporting them out of the mine.
Miners in a vehicle ahead felt a blast of air and went back to find out what happened, finding several of their co-workers dead and two injured.
Rescuers had been trying to reach at least 10 trapped miners further into the mine, but some of them also appear to have been found dead.
Officials say four miners are still unaccounted for. They were carrying at least an hour's worth of oxygen and could have access to a further 96 hours if they were able to reach one of the mine's refuge chambers.
Massey Energy says on its website that it has a safety record that is above the national average, with three fatalities in the last 12 years.
But federal inspectors have fined the company more than $382,000 for serious violations at the mine over the past year, the Associated Press reports.
Last year 34 miners were killed in accidents across the US, the lowest on record.
But the Upper Big Branch accident is the biggest since 1984, when 27 people were killed by a fire at Emery Mining Corp's mine in Orangeville, Utah.