A wildfire that broke out at Britain’s North York Moors National Park has burned for weeks, reaching a ground layer containing unexploded ordnance from World War II.

The Langdale Moor fire started on Aug. 11, the North Yorkshire Fire and Rescue Service said. Crews from the North Yorkshire service and other local firefighting departments were still fighting the blaze Thursday.

The fire is affecting an area of almost 10 square miles according to the BBC, and is fueled by wind, vegetation and now peat. The peat layer also contains decades-old unexploded bombs and other ordnance from World War II.

“As the peat continues to burn down, it is finding the World War II ordnance and therefore exploding and we have now experienced over 18 ordnance explosions within key areas,” North Yorkshire Fire Chief Jonathan Dyson told the BBC.

The British military used the Langdale Moor area as a tank training ground during the war, and the possibility of more bombs has forced firefighters to adopt a defensive strategy in containing the wildfire.

The wildfire is far from the first time old ordnance has posed issues for modern-day Britain. A playground in Wooler was delayed for months after workers uncovered a cache of practice bombs. The playground finally opened earlier this month.

• Brad Matthews can be reached at bmatthews@washingtontimes.com.