A man has died and three others have been injured following an incident at an industrial unit.
Bedfordshire Police was called to reports of a suspected explosion at the unit off Brunel Road in Bedford, at about 15:50 BST.
People on social media reported hearing a loud bang from nearby Priory Country Park.
Officers plan to stay on site until the investigation has been handed over to the Health and Safety Executive.
The force said an initial cordon put in place for people’s safety had since been removed.