Clashes took place in Buthidaung township in the northern part of Rakhine late on Thursday shortly after rebels from the Arakan Army, battling for greater autonomy for the region, met representatives of the military in the capital, Naypyitaw.
Rakhine State came to global attention after the Myanmar army drove about 730,000 ethnic Rohingya Muslims across the border into Bangladesh late in 2017, but ethnic Rakhine are largely Buddhist, like the majority of Myanmar’s people.
Photographs taken by a Rakhine lawmaker and obtained by Reuters show the blood-smeared bodies of four people, including a young boy and a middle-aged woman, lying in a dusty pit.
"They are civilians who were hiding in a bomb shelter," said Maung Thar Phyu, a civil society activist in the area. "It is terrible."
Military spokesman Brigadier-General Zaw Min Tun told Reuters by telephone there had been a battle to the south of Say Taung village at around 9 p.m.
He said the rebel Arakan Army had initiated the clashes and the incident would be investigated further.
An Arakan Army spokesman did not immediately respond to telephone calls from Reuters to seek comment.
The Rakhine MP who traveled to the area on Friday said residents told him soldiers had surrounded the village late on Thursday and bombarded it with heavy weapons.
"We brought five bodies...to Buthidaung town now," said Maung Kyaw Zan, an MP for the area. Six people were injured, with one dying later in hospital, he said, adding that all the other villagers had fled.
About 7,500 displaced people are scattered across 29 sites in Rakhine, the Myanmar office of the UN Office for the Coordination of Humanitarian Affairs said in a statement.
For weeks, most humanitarian agencies have been blocked from delivering aid to vast areas across the state's north.
"It is estimated that at least 95,000 people ... have been affected by access restrictions in the five townships of Kyauktaw, Ponnagyun, Buthidaung, Maungdaw and Rathedaung," the U.N. agency said.
Peace talks between the government and the Arakan Army rebels concluded on Thursday without significant agreement, though they signed a pact to continue talks.Myanmar governments have battled various ethnic minority insurgent groups since soon after independence from Britain in 1948, though some have struck ceasefire deals.