Myanmar's army has said it shot dead at least six people detained in a village school in Rakhine state.
A spokesman confirmed troops fired on unarmed detainees saying they had tried to grab the soldiers' weapons.
The detained were being questioned for links to the rebels of the Arakan Army, who are ethnic Rakhine Buddhists.
More than 30,000 mainly Buddhist civilians have been displaced in the latest fighting between national forces and the rebels.
A multi-ethnic country, Myanmar is home to a number of rebel groups.
While a lot of attention in recent years has been on the exodus of the Muslim Rohingya to Bangladesh, other ethnic minorities also clash frequently with the government's military.
Journalists and most aid agencies are banned from northern Rakhine and it is hard to verify what happened on Thursday morning, the BBC's Nick Beake in Yangon says.
Army spokesman Brigadier General Zaw Min Tun told news agency AFP that 275 people "were being temporarily held in the village school for investigation" in Kyauk Tan village in Rathedaung township.
Early Thursday morning, shots were fired when the detainees tried to "attack the security forces", Zaw Min Tun added, saying soldiers had no option but to shoot.
He told AFP that warning shots had been fired first but that "six were killed, eight were injured and four escaped".
But Ma Gne - a widow of one of the men shot dead - told AFP that her husband and the others "were killed for no reason".
The victims' families said the bodies of the dead were laid out in front of the school.
The impoverished state of Rakhine in western Myanmar has seen years of fighting and unrest.
Since 2016, Rakhine has also seen the exodus of hundreds of thousands of Rohingya Muslims.
UN officials believe Myanmar's army may have committed war crimes against the Rohingya - a charge it denies.