A School Discovered Bombs in Its Backyard: What to Know About the Deadly Legacy of Decades-Old, Unexploded Weapons in Cambodia

While trying to expand its garden last Friday, a high school in northeastern Cambodia was forced to temporarily close after an unexpected discovery on its grounds: thousands of unexploded weapons.

Over the next three days, deminers found over 2,000 devices buried in the soil at the Queen Kosomak High School, which more than 1,000 students attend. “It is a huge stroke of luck for the students. These explosive devices are easy to explode if someone dug into the ground and hit them,” Heng Ratana, director general of the Cambodian Mine Action Centre, told AFP on Sunday.

Lessons will be held online until it is safe for classes to resume, the Queen Kosomak High School management announced in a Facebook post on Monday.

The newly unearthed explosives, which include grenades and anti-tank launchers covered in rust, are remnants from Cambodia’s civil war which ended some 20 years ago. Provincial education officials said that the compound was used as a munitions warehouse in the 1970s during the Khmer Rouge regime and was wrongly believed to have been cleared of explosives when it was later converted into a school.

It’s not just Cambodia that’s haunted by weapons from conflicts of the past. Decadeslong campaigns have also been underway in neighbors Vietnam and Laos to clear unexploded landmines and cluster munitions that remain littered across Southeast Asia from the Vietnam War. As these types of weapons continue to be used in other parts of the world today, some fear their deadly legacy will be felt by future generations in similar ways.

Despite international treaties being signed by most countries (though not the U.S.) banning the use of landmines and cluster munitions, both known for their indiscriminate nature, the weapons have continued to feature in recent conflicts—including in post-coup Myanmar, where the fighting between junta forces and resistance groups has seen 390 people killed or injured by landmines and unexploded ordnance last year.

Read More: The Military Tried to Burn Thantlang Down: How a Myanmar Township Defied the Odds to Become a Resistance Stronghold

In Ukraine, now the world’s most mined country since Russia’s invasion last year, landmines and explosive remnants of war killed 226 people in March alone. Meanwhile, the U.S. sent cluster bombs to Kyiv last month despite warnings by authorities in Cambodia and Laos.

Cambodia knows too well just how tedious it is to reverse the damage wrought by these types of weapons. Here’s how the country has continued to deal with their effects.

How serious is Cambodia’s explosives problem?

Landmines were planted by various sides during the Cambodian civil war which stretched for 30 years before it ended in 1998 with the surrender of surviving leaders of the Khmer Rouge regime.

Read More: 40 Years After the Fall of the Khmer Rouge, Cambodia Still Grapples With Pol Pot's Brutal Legacy

Today, decades after the explosives were first sown, unsuspecting Cambodians continue to bear the brunt of their explosions, with dozens killed every year, especially in rural areas. Many of these victims are children who were playing in fields or scavenging for scrap metal. In 2016, two children were killed after playing with an unexploded grenade they found while hunting for birds. Last year, an anti-tank mine exploded and killed three deminers and injured one in the northern province of Preah Vihear. 

Almost 20,000 people were killed by exploding landmines and other ordnance between 1979 and August 2022, according to the Cambodian Mine Action and Victim Assistance Authorities. The widespread use of such explosives has also resulted in Cambodia having one of the world’s highest number of amputees per capita, with over 40,000 amputees in the country of 16.6 million.

Authorities estimated in 2010 that there could be four to six million mines and ordnance strewn across the country. Today, about 800 square kilometers of land still contain landmines while over 650 square kilometers of land are contaminated by cluster munition remnants, according to Landmine and Cluster Munition Monitor.

What do demining efforts look like?

There are several NGOs in Cambodia focused on removing lingering explosives and mitigating their impact, as well as a number of demining programs supported by international organizations and foreign governments, including South Korea, China, Canada, and Australia.

About four million unexploded landmines and munitions were removed between 1992 and 2018, but demining efforts are still ongoing. The ultimate goal, according to the Cambodian government in 2020, is to make the country mine-free by 2025—which observers described at the time as ambitious but achievable. 

With authorities planning to clear over 400 square kilometers of landmines this year, the Cambodian Mine Action and Victim Assistance Authority said in April that they would need an additional $138 million, calling on the international community for funding to meet the target.

Global non-profit organization APOPO, which has been supporting demining efforts in Cambodia since 2014, has also introduced more novel methods of detecting buried explosives—to considerable success. Over the last couple of decades, the group has trained hundreds of what they call “hero rats,” trained to sniff out landmines while scurrying across explosive-ridden terrain, making them much faster than humans holding metal detectors. Magawa, one such rat who detected more than 100 explosives during his five years in Cambodia, died last year at eight years old and was hailed as an international hero.

Cambodian deminers, by now known for their expertise in the field, have even been deployed to other parts of the world, including Africa and the Middle East, to help with demining. In November last year, Cambodia agreed to dispatch deminers to Ukraine to help train locals to clear landmines planted by Russian troops.

The country’s leaders are also warning other countries to learn from its experience. On July 9, Prime Minister Hun Sen publicly urged Ukraine to refrain from using cluster munitions that the U.S. said it would be sending. The bombs arrived in Ukraine four days after Hun Sen wrote of the ongoing fallout in his country from their use, cautioning: “It would be the greatest danger for Ukrainians for many years.”