Huge plumes of smoke have engulfed the skies of northwest England on Sunday (4 December) as a blaze erupted at a hazardous waste site near Liverpool.
Explosions could be heard from the site in Prescot, Merseyside, since the fire started at 6am.
The blaze has since raged for hours and is believed to encompass an area greater than 1km sq.
More than 80 firefighters still trying to tackle blaze, which Merseyside Fire and Rescue service saying it could "burn for days".
A spokesman for the service said: "Firefighters continue to fight a major fire at a waste facility in Carr Lane, Prescot.
"Half of the building nearest to Carr Lane is fully involved in the fire and part of the building is beginning to collapse.
"The area involved has been divided into sectors and main jets and breathing apparatus are in use in firefighting.
"Residents are advised to continue to observe safety advice as before until further notice."
Twitter user Ubik said: "Audible explosions still being heard in surrounding area".
The site – a state-of-the-art hazardous waste transfer and recycling facility – where the fire is taking place belongs to German firm Remondis.
They completed building the site in 2013, costing the company £8.5m ($10.8m), reported the Liverpool Echo.
It is said to process up to 69,000 tonnes of materials each year and is said to be operational 24 hours and 365 days of the year.
Prescot North councillor Carl Cashman said to the Liverpool Echo: "We've potentially got a real environmental disaster. I'd like the facility to close for the imminent future and in the long term too.
"It's extremely worrying as we don't know what heavy duty hazardous waste they're burning in there."
The Environment Agency said in a statement: "We are working with partner agencies including Merseyside Police, Public Health England and Merseyside Fire and Rescue Service to ensure the risk to people and the environment is minimised."
Remondis UK and Public Health England are yet to comment on the fire.