City Hall is cracking down on the unauthorised excavation of soil and sand from the capital, ordering all businesses engaged in such activities without proper paperwork to cease immediately.

The order, announced on Tuesday, came a day after a Z-9 military helicopter crashed in a former sand quarry in Phnom Penh’s Prey Sar district on Monday, killing four military officers, which City Hall spokesman Long Dimanche said prompted the ban.

“Because of the military helicopter crash in that area, we found that the company owner who dug the deep ditch in that area had violated our authorisation to dig there,” he explained.

Dimanche added that the municipality had granted permission for some companies to excavate to a depth of 15 or 20 metres, adding that he was unaware of how many businesses had abused the law.

“Businessmen who are in Phnom Penh and are digging without licences have to stop. If the businessmen do not comply with the announcement, Phnom Penh Municipal Hall will take tough measures,” the statement says.

It adds that the digging of deep sand quarries had “seriously affected development and the environment”, creating a situation of “anarchy” where the mined materials were being used to fill in ponds and reservoirs needed to store rainwater, which in turn exacerbated the risk of flooding in the capital.

Cheak Earng, director of Phnom Penh’s environment department, yesterday declined to comment on the environmental impact and increased risk of flooding caused by the mining of earth and sand.

Nhem Vanda, vice president of the National Committee for Disaster Management, said the hole dug at the site where the Z-9 helicopter crashed was in violation of the city’s regulations, as it was “at least 30 metres deep”.

Following the recovery of the craft’s black box on Monday, six Chinese aviation experts were due to arrive in the capital yesterday to assess the device, according to Air Force Commander Soeung Samnang, but they could not get plane tickets so are expected to arrive in Phnom Penh today.

When the specialists arrive, a commission of inquiry will be set up by authorities and the black box sent to the Chinese manufacturer, he added.

Three of the four military officers killed in the crash were cremated at Pochentong Air Force Base yesterday, while the body of Major General Ouk Bunnaha, a deputy commander of the helicopter unit, was buried in Meanchey district’s Prek Pra commune.

Cambodia bought 12 Z-9 helicopters with a $195 million loan from China in November last year.