Houses within a two-mile radius of the drilling rig near Watonga, about eighty miles northwest of Oklahoma City, were evacuated after the blast at about 10pm local time last night.
About a dozen workers were also evacuated.
Witness Matt Miller told KOCO-TV: 'The flames were probably 100-feet tall. Periodically, there were explosions with huge flashes.'
Witness Maria Slay told The Oklahoman that she heard four or five explosions.
Nobody is thought to have been injured in the blast. Read More