LONDON (AP) — Some 120 firefighters are trying to contain a wildfire that has been declared a "major incident" as it spreads in the moorlands of northern England.

British fire officials said two large fires had merged because of high winds and extremely dry conditions as much of England is gripped by a heat wave. The fire is in the Winter Hill area, 220 miles (355 kilometers) northwest of London.

Lancashire fire officials said late Saturday that "we are dealing with a rapidly developing aggressive fire across all vegetation types, including woodlands."

About two dozen fire engines are on the scene and steps are being taken to protect nearby properties. Officials are asking residents not to come to try to help because of the threat to public safety.