Two high-ranking officers were fired for having “failed their responsibilities” after a landslide in Myanmar killed at least 174 jade miners, the country’s military said on Monday in a rare public sanctioning.

Heavy monsoon rains on Thursday sent mud cascading down a hillside over workers scouring the land for the green gemstone in Mohnyin district’s Hpakant township in northern Kachin state.

The victims were largely poor migrants who had travelled across the country to prospect in the treacherous open-cast mines, hoping to find valuable stones left behind by the big companies.

It was the worst tragedy in living memory to hit the shadowy, multi-billion dollar industry.

A Facebook post on Monday by the military announced that Kachin state Security and Border Affairs Minister Colonel Nay Lin Tun and another unnamed commander had been removed from their posts.

Spokesman Brigadier General Zaw Min Tun said: “They were responsible for reporting any trespassing in this restricted area . . . They failed their responsibilities.”

He said the military will hold an investigation and appropriate action against the two men would be taken.

Unidentified miners have been buried in mass graves, while many more remain missing.

They join scores of informal prospectors killed each year in Hpakant as they search for the stone so highly-prized over the border in China.

The industry is mired in secrecy. UK-based environmental watchdog Global Witness alleges that operators are linked to the military elite and its cronies.

The group estimated the industry was worth some $31 billion in 2014, although very little reach state coffers.

Some compensation has been handed to the families of the deceased, but observers have criticised the government for a perceived lack of sympathy.

Minister of Natural Resources and Environmental Conservation Ohn Win told local media on Sunday that “greedy” miners were to blame while civilian leader Aung San Suu Kyi has not released a formal statement.

Ethnic Kachin insurgents and the military have been fighting over northern Myanmar’s natural resources and the revenues they bring for decades.

The whole industry is a “massive organised crime operation” that exploits those at the bottom, said Yangon-based independent analyst Richard Horsey.