This summer's wildfires haven't just torched forests and farmland across Europe. They've been setting off bombs.
In France, Belgium, Germany and the Netherlands, fire crews battling blazes fuelled by drought and record heat have had to work alongside bomb disposal teams, as heat and flame reach munitions that have sat quietly underground since the two world wars. Jonas Tepe, a regional government spokesperson in North Rhine-Westphalia, Germany, has noted that unexploded ordnance becomes more dangerous specifically around wildfires because heat alone can be enough to set explosives off, without direct contact with the flames. In the French village of Le Porge, near Bordeaux, a wildfire uncovered roughly 400 shells and pieces of ammunition, mostly German and French mortar rounds and anti-tank shells, according to French officials. One resident told regional media that a piece of the recovered ordnance had gone straight through a house.
In eastern Belgium's Liège province, home to the WWII-era battlefields of the High Fens, the regional governor confirmed sporadic detonations during recent fires, with local emergency services adapting their response to account for buried munitions. A Dutch bomb-disposal unit was separately sent to check a forest near a former WWII combat site in Limburg as flames approached.
This isn't a one-off. Belgium's Explosive Ordnance Disposal and Destruction Service handles more than 3,000 call-outs a year, clearing 200 to 250 tonnes of old munitions annually. In Ypres, the WWI battlefield town, farmers have a name for the debris that turns up every time they till a field: the "iron harvest."
It reads like a historical curiosity. For UK insurers and brokers, it's something closer to an early warning.
Britain has its own version of this landscape. Peat-rich moorland such as the North York Moors, used for tank training during the Second World War, holds buried ordnance in ground that is becoming increasingly prone to burning as summers get hotter and drier. That's not a new observation; the UK has been dealing with legacy munitions on construction sites for decades. But it lands differently in a year when wildfire has quietly stopped being a peril that only shows up in reinsurance cat models for Mediterranean exposure, as Insurance Business UK reported last month, with wildfire detections recorded within five kilometres of London itself.
The mechanism linking fire to buried explosives is fairly simple physics. Burning off surface vegetation and topsoil can expose shells and mines that were previously buried too deep to be disturbed, leaving them lying in the open where heat, impact or handling can set them off. Peace and conflict researcher Dr Sarah Njeri of SOAS, University of London, who studies the environmental legacy of landmines and unexploded ordnance, argues that steady, predictable weather patterns used to keep this kind of buried contamination inert. She describes that stability as Europe's "climatic luck" running out: climate change, in other words, is doing the work of digging up and reactivating hazards that had been dormant for the better part of a century.
The scale of this year's fire season is part of the context. The EU's satellite-based European Forest Fire Information System had recorded upwards of 500,000 hectares burned across the bloc by early August 2026, already ahead of the same point in 2025, itself the worst year on record. That figure moves daily, so it's worth checking the live dashboard for anything current rather than treating this as fixed. The direction of travel is the point: more burned land means more exposed ground, and more exposed ground means more of this kind of find.
This is where it stops being purely a civil protection story and becomes a coverage question. The UK courts have already answered it, at least in one high-profile case.
In 2021, construction workers at the University of Exeter unearthed a live German bomb dropped on the city in 1942. It couldn't safely be moved, so bomb disposal experts carried out a controlled detonation, which damaged nearby halls of residence. The University claimed under its property policy. Allianz declined, citing the standard market War Exclusion Clause for loss "occasioned by war." The dispute went to the Court of Appeal, which in late 2023 unanimously sided with the insurer. Its reasoning, set out in the full judgment on BAILII, was that the dropping of the bomb in 1942 and the controlled detonation nearly 80 years later were concurrent proximate causes of the loss, of roughly equal weight. Because one of those causes fell squarely within the war exclusion, the whole claim was barred. Proximate cause, the court noted, doesn't mean whichever event happened last. “There were two concurrent causes of the loss and damage: the dropping of the bomb and its detonation,” wrote Lord Coulson.
That ruling matters well beyond one university campus. Any UK property with legacy ordnance nearby, be it a rural estate, a heathland business park, or a housing development on former military land, could face the same argument if a fire or excavation forces a controlled detonation. Brokers advising clients with exposure in historically bombed or requisitioned areas should treat war exclusion wording as live risk, not boilerplate, particularly as UK wildfire activity moves closer to residential and commercial property rather than staying confined to remote moorland.
What a war exclusion clause actually excludes. Most UK commercial and property policies carry a standard-form clause excluding loss "occasioned by war," alongside similar wording for invasion, hostilities and civil war. It's boilerplate that rarely gets tested until a claim like Exeter's shows up. The Court of Appeal's key finding was on proximate cause: where two events combine to cause a loss and one of them falls within an exclusion, the exclusion can still defeat the whole claim, even if the other event (here, a 2021 controlled detonation) was recent, deliberate and carried out by professionals with no connection to the original wartime act. Age doesn't dilute causation. Clients who assume "it happened 80 years ago" is a defence in itself should be told otherwise.
Legacy ordnance is worth folding into the wider wildfire conversation, not treating as a separate box to tick. Land that was requisitioned or bombed during the world wars often overlaps with the heath, moorland and forest driving the UK's record wildfire seasons, so a desktop UXO risk search, already standard practice for construction sites under the industry's CIRIA C681 framework and its newer companion guide for land-based projects, CIRIA C785, is worth revisiting for rural and heathland property books more broadly.
War exclusion wording is worth reading properly at renewal rather than skimmed as boilerplate. Following University of Exeter v Allianz, "occasioned by war" language can bite even when the damage is caused by a modern, deliberate act, provided a historic act of war remains a concurrent proximate cause.
It's also worth flagging alongside other compounding ground exposures. Some insurers are already treating drought-driven subsidence and wildfire as a single, compounding risk in affected postcodes, a shift covered in Insurance Business UK's reporting on the West Midlands fires. Legacy ordnance looks like a third strand of the same ground-hazard story: dry conditions don't just crack foundations and fuel fires, they can also disturb what's buried beneath them.
And it isn't only a France-and-Belgium problem. European Commission satellite monitoring shows 2026's burn area running ahead of the same point in 2025, itself a record year, and the underlying cause, heavy winter and spring rain fuelling summer-dry vegetation, applies to the UK too.
Not every rural policyholder is at risk of a wartime bomb going off in their back garden. But this year's fire season, a market already reassessing its wildfire and subsidence assumptions, and a Court of Appeal ruling insurers can lean on with confidence, make the buried-ordnance angle a detail worth having on file.
