Two Cambodian deminers who spent their days helping to identify and remove deadly remnants of past wars were killed on Saturday morning when an anti-tank mine exploded at a work site in Battambang province, according to the organisation that employed them.

The HALO Trust, a UK-based demining nonprofit organisation that has been in Cambodia since the 1990s, said its deminers, Phin Nout, 30, and Chhum Chai, 44, died in the province’s Samlot district. An investigation into how the accident occurred is under way in conjunction with the Cambodian Mine Action Authority.

According to HALO Trust program manager Adam Jasinski, who released a statement about the explosion, Nout was a 10-year veteran of the organisation, while Chai had worked there since 2008.

“Both men were greatly respected members of the HALO Trust team who had dedicated many years to ridding Cambodia of the threat of landmines. Our thoughts are with their families, who are currently receiving support,” Jasinski said.

Chai is from Sisophon town in Banteay Meanchey province and has two children. His younger colleague, Nout, is from Phnom Proek district in Battambang.

The accident comes more than a year after four experts with demining NGO Golden West Humanitarian Foundation were wounded in January 2013 while disabling anti-aircraft ammunition at their training centre in Kampong Chhnang province.

Srey Chantha, an official in charge of victim data in Battambang for the Cambodian Mine Action Centre (CMAC), said the two men were combing the area on Saturday when the explosion occurred.

“An anti-tank mine is capable of destroying anything within 100 square metres, so people who are in this perimeter cannot escape or survive,” Chantha said.

Sam Som, Samlot commune police chief, said that according to local villagers, the explosion blew one of the deminers 50 metres from the source, while the other man’s body was torn into pieces.

“Only 2 kilograms of the body’s pieces were found and collected,” he said.

Samlot had been a battlefield for nearly 50 years, starting with clashes in the mid-1960s. During the rule of the Vietnamese-backed government some two decades later, countless mines were laid in the area and all along the Thai border in what was known as the K5 project.

As recently as the late 1990s, when Khmer Rouge fighters defected to the government, former Khmer Rouge leaders deposited anti-tank mines there to protect the location in case conflict flared up again.

“Samlot is one of the heavier mine-affected districts, specifically anti-tank mines; it’s quite heavy,” said Heng Ratana, director general of CMAC.

Unexploded ordnance (UXO) claimed the lives of 22 people in 2013, down from 43 in 2012. But this year has not gotten off to a good start.

Forty were injured or killed by landmines and other UXO in the first two months of 2014, a figure nearly twice as high compared with the same period last year, a report from CMAC shows.

Deminer fatalities, however, are extremely rare. Since HALO Trust started working in Cambodia in 1992, there have been six deminer deaths, including the two on Saturday. In those 22 years, HALO Trust has destroyed more than 265,000 mines and 168,000 pieces of unexploded ordnance. About 1,000 Cambodians are employed by the organisation.

Still, it’s a risky job, and it does happen, said CMAC’s Ratana.

“Even with skilled deminers.”