A significant gas leak has seen hundreds of people evacuated in West Sussex during what police declared a "major incident".
The incident reportedly occurred at a large block of flats in Melton Mount Avenue, Crawley, at 12.21am, with around 700 residents evacuated and placed in temporary accommodation, Sussex Police said in a statement.
The response included personnel from West Sussex Fire and Rescue Service, South East Coast Ambulance Service, West Sussex County Council, Crawley Borough Council and Southern Gas.
Sussex Police detective chief superintendent Steve Rayland said: "This is an ongoing incident which has caused huge disruption to hundreds of people on a cold January morning, and I’d like to thank everyone for their patience and understanding as we continue to work with our partners to minimise the ongoing disruption.
"We are working hard to ensure this is dealt with as soon as possible to enable everyone to return home, however this may take several hours yet.
"In the meantime, we are urging everyone to stay away from the area to allow the responding agencies to focus on resolving the incident to allow residents to return home.
"The exact cause of the gas leak is yet to be determined but not believed to be criminal, and we will provide more information as soon as we are able to."
Resident Leah Hicklin said she was evacuated at 1.30am but said that others were still being led from the building at 4am.
She told the BBC: "We thought it was only something minor until they started evacuating the minor floors and then I was the top floor and I could smell gas.
"So they slowly but surely evacuated every single one of us. Some are in hotels, some are at family, some people really didn’t know where they were going. They’ve left pets behind and whatnot."