Hundreds of residents remain in Pauktaw town, Rakhine State, since Myanmar junta troops raided on Thursday.
The Arakan Army (AA) seized Pauktaw Township police station on Wednesday and then the rest of the town before junta helicopters attacked and naval vessels shelled the town.
On Thursday over 100 troops raided Pauktaw and shot dead around 10 residents.
A Rakhine volunteer said: “Junta troops shot at least 20 people and half of them died. Volunteers could not treat them or take them to Sittwe hospital.”
The Irrawaddy could not independently verify the reports.
The Arakan Army (AA) said on Friday that it would retaliate for the bloodshed.
“The junta troops committed a war crime in Pauktaw. We are very sad for those civilians killed and we will retaliate,” said the AA.
Residents who fled the town say they cannot find food amid junta blockades and about 1,000 town residents remain trapped in their houses. The junta has cut off electricity in the town.
Ma Phyu Phyu, 27, said her sick father remained in their house with her younger brother when she left the town on Friday.
“My father had a paralytic stroke so I left him with my little brother. They have no food and they can’t leave the house,” she said.
Displaced residents say most people remaining in the town are vulnerable, elderly or unhealthy.
Pauktaw had about 20,000 residents, according to the regime’s general administration department. The United Nations Office for the Coordination of Humanitarian Affairs estimated on Friday that 19,000 people had been displaced from Pauktaw.
Civilians say they fear a junta clearance operation in the villages around Pauktaw.