A blaze at a major oil refinery has been brought largely under control by firefighters.
Despite the "aggressive" fire, which produced thick black smoke clouds, there has been no disruption to operations at Stanlow Oil Refinery, Ellesmere Port, in Cheshire, its operator said.
All staff at the site were evacuated and are accounted for after emergency calls were made at 2.16pm on Wednesday,Cheshire Fire Service said.
It is believed the blaze started inside a manufacturing building within the plant.
The refinery employs more than 900 staff and an additional 500 on-site contractors, and supplies 16% of all UK road transport fuels, according to operator Essar Oil UK.
Brian Howell, 60, said he was relaxing in the Eastham Ferry area, around eight miles away, before he "heard a loud 'whoosh' type explosion".
He added: "I looked over to Stanlow and there was an aggressive fire and lots of black smoke."
Six fire engines attended the scene in Oil Site Road and as of 3.30pm crews were using handheld equipment to extinguish pockets of flame, the fire service said.
The fire has not disrupted the refinery's operations, a spokeswoman for Essar Oil UK said.
The Environment Agency said it was working with the fire service to try and reduce any harmful environmental effects.
Firefighters worked with on-site staff to deal with the unfolding emergency.
Stanlow has a team of 25 full-time staff to allow for immediate action to prevent potential catastrophes.
The refinery produces 4.4 billion litres of diesel, three billion litres of petrol and two billion litres of jet fuel annually, according to Essar Oil UK.