A pile of grass cuttings self-ignited on the edge of a nature reserve and a girls’ grammar school yesterday.

Firefighters were called to the blaze on the boundary of Warren Farm and playing fields at Nonsuch High School for Girls in Cheam just after 4.30pm.

An Epsom fire station spokesman said: "The grass decomposes and warms up and in the end it was starting to smoulder and ignite. There were some flames."