The reported explosions and fire happened at a building on the former site of the chocolate company Thorntons, the BBC reports.
Belper residents advised not to pick up any debris following fire on Derwent Street as it may contain asbestos. Contact police on 101
Witnesses have reported hearing a series of explosions at a industrial site in the Derbyshire town of Belper.
Pictures circulating on social media show billows of black smoke above the site.