The collapse occurred Saturday afternoon in Kachin state, said Brang Seng, a jade businessman, describing rows of bodies pulled from the debris.
"This is awfully bad," he said, adding that he saw more than 70 bodies pulled.
More than 100 other people were missing, said Lamai Gum Ja, a community leader who also has interests in the mining business. He said an official at the scene reported that 60-70 bodies had been pulled from the rubble.
Myanmar only recently started moving from a half-century of dictatorship to democracy. Hpakant, the epicenter of the country's jade boom, remains desperately poor, with bumpy dirt roads and constant electricity blackouts.
The region bordering China is home to some of the world's highest-quality jade, bringing in billions of dollars a year, though researchers say most of that money goes to individuals and companies tied to Myanmar's former military rulers.
Informal miners risk and often lose their lives digging through scraps of the giant mines.
"Large companies, many of them owned by families of former generals, army companies, cronies and drug lords, are making tens or hundreds of millions of dollars a year through their plunder of Hpakant," said Mike Davis of Global Witness, a group that investigates the misuse of revenue from natural resources.
He said that "scores of people at a time are buried alive in landslides."
Related story
Desperate search for missing girls as nearly 80 dead in Texas f...
