A "major incident" has been declared and casualties reported after reports of an explosion at Didcot Power Station.
Thames Valley Police said it was called at 4pm to the site in south Oxfordshire alongside other emergency services.
Six ambulances and two air ambulance have been sent to the scene, South Central Ambulance Service said.
A spokesman said: "We are describing it as a major incident" adding that he thought there would be casualties.
Photographs from the scene showed part of a building missing, which appears to be the former coal-fired Didcot A, which closed in 2013.