A major incident has been declared as firefighters battle a large heathland fire on the Suffolk coast.

Suffolk fire and rescue service was called to reports of a wildfire at Dunwich Heath, near Leiston, shortly after 5.30pm on Wednesday, and crews remained at the scene on Thursday morning. About 90 firefighters were tackling the blaze, while several people had been evacuated.

The fire was spreading south-west, the service said, confirming that a major incident had been declared “due to the size and complexity” of the blaze. People have been urged to avoid the area where possible and keep windows and doors closed.

As a precaution, crews have been focused on protecting nearby properties, while preparations have been made for the potential to evacuate about 200 caravans at the Cliff House holiday park if conditions deteriorate.

Dan Davis, a station manager with Suffolk fire and rescue service, said: “Crews from Leiston attended the scene and were met with what is a large-scale, wind-driven forestry fire.

“The incident has subsequently been upgraded to a major incident. We currently have approximately 90 firefighters on scene working incredibly hard in arduous conditions to bring this fire under control.”

People displaced by the fire have been advised to attend Westleton Village Hall at 8am for further updates.

Specialist drones were being overnight to assess fire behaviour and support operational decision-making, while crews also deployed multipurpose all-wheel-drive Unimogs and 4×4 quad bikes.

The UK Health Security Agency had issued an amber heat-health alert for the East Midlands, the east and south-east of England and London, which was to remain in place until 9am on Thursday. The agency has warned that rising temperatures could increase health risks, particularly for vulnerable groups.

In Scotland, crews said they were making significant progress tackling a wildfire in the Cairngorms that broke out two weeks ago.