A coal mine explosion in a Massey Energy Company mine in West Virginia, US, has killed at least 25 miners and left four trapped 1,000ft down in the country’s worst mining disaster in 26 years.

The explosion occurred at the Upper Big Branch mine in Raleigh County in a region where a total of 29 miners were working.

US Federal Mine Safety and Health Administration spokesman Kevin Stricklin said the miners were on their way out of a mine in a vehicle when the blast occurred.

Stricklin said that the explosion destroyed all communication lines inside the mine.

The cause of the blast is yet to be verified, but critics say the mine had been penalised before for violating safety regulations, including those surrounding proper ventilation for highly combustible methane gas.

The mine is owned by the Virginia-based Massey Energy and operated by Performance Coal.