Around seventy firefighters have been tackling a blaze at Glandwr Industrial Estate near Aberbeeg. It broke out just after 1am and spread to a garage and a carpet warehouse. Officers say there has been a partial collapse of a building.
Arriva Trains services between Ebbw Vale Parkway and Crosskeys have been replaced by buses. And a primary school has been closed. Residents are also being warned to close windows.
South Wales Fire and Rescue Service say they will be at the scene for several hours. An investigation will then be carried out to find out what caused the fire.