Flames and smoke billow as firefighters deal with a serious fire in a tower block at Latimer Road in West London, Britain June 14, 2017. [Photo by Lei Xiaoxun/chinadaily.com.cn]

"This is a large and very serious incident and we have deployed numerous resources and specialist appliances."

More than 20 ambulance crews were at the scene. London Mayor Sadiq Khan said a "major incident" had been declared. Police closed the A40, a major road leading out of west London, while some parts London's underground train network were closed as a precaution.

The cause of the fire, which broke out just before 1 am (0000 GMT), is not known, the Fire Brigade said. Residents said repairs, including the addition of some sort of cladding, had been made to the exterior of the block recently.

Reuters