The Arakan Army (AA) said an attack by two military fighter jets on Monday killed six of its members and left scores injured.
The bombing also damaged a hospital, a clinic and a garment factory in the area near the Thai border, controlled by AA ally the Karenni National Liberation army
Witnesses said the jets flew into Thai airspace after the bombings.
The dead were identified as Kyaw Oo Hlaing, Kyaw San Htay, Tun Lin, Bo Than Kyaw, Nay Zaw Oo, and Zar Ni Win, aged between 20 and 31.
Rakhine residents have been posting messages on Facebook mourning those killed in Monday’s air strike.
Calls to the military council spokesman by RFA went unanswered. AA spokesman Khing Thukha told local media outlets that his troops were not fighting with junta forces in the area. He said the airstrike was unprovoked and the AA plans to retaliate.
Pe Than, a former People’s Assembly member from Rakhine State, said that the junta’s bombing of the AA could lead to renewed fighting.
“We all know who lives there and whose camp is this,” he said. “That means this was a deliberate attack. [The junta] have to attack these camps because of the situation in Karen State. [In spite of a ceasefire] the military sees the AA as the enemy, so the lull in fighting during the ceasefire is unlikely to last.”
The military council and the AA agreed to a ceasefire, which has largely held for more than a year.
The AA operates primarily in Rakhine State, where it is seeking autonomy from the ethnic Rakhines, but also operates in other states, including Kayin (Karen) state.
It has been a long and bitter conflict. On November 19, 2014, 23 cadets from the Ta’ang National Liberation Army (TNLA), Chin National Front (CNF), All Burma Students Democratic Front (ABSDF), and eight cadets from the AA died when the military shelled their training academy in Laiza, Kachin state.
Myanmar’s shadow National Unity Government (NUG) has invited the AA to join an alliance of regional armies to fight the military, which could also lead to an escalation in violence. The AA has so far ignored the NUG’s overtures and instead focused on its own territorial ambitions.
But tensions between the junta and the AA have been high since early May, with locals and Rakhine politicians concerned that fighting will soon intensify.
The resumption of full-scale conflict between the military and the AA could put the lives of millions of ethnic minority residents of Rakhine at risk, according to a report published this month by the International Crisis Group (ICG), an NGO.
It said AA efforts to gain territory in the north could affect as many as 3 million ethnic Rakhines and Rohingyas. Tom Kean, ICG senior adviser on Myanmar, told RFA this month that a humanitarian consequences from renewed fighting would probably be worse than they were during the two-year war.
ICG said the group now controls between half and three quarters of Rakhine, Myanmar's westernmost state which borders Bangladesh and the Bay of Bengal.