At least two policemen were killed in coordinated attacks by an unknown group on posts along Myanmar's border with Bangladesh early Sunday morning, an official and police said.
The assaults hit three border posts around 1:30 am (1800 GMT Saturday) near Maungdaw in Rakhine, an impoverished state on Myanmar's western flank simmering with sectarian tensions between Buddhists and Muslims.
"According to initial information, two police officers were killed, two others were injured and six police are missing," Tin Maung Swe, a senior official within Rakhine's state government told AFP.
A police official in the capital Naypyidaw confirmed three places were attacked but declined to give further details.
A second police source also confirmed the attacks, adding as many as eight policemen might have been killed, as well as some of the attackers.
A number of weapons were also seized by the assailants from the border posts, that officer added.
Rakhine has been effectively split on religious grounds since bouts of communal violence tore through the state in 2012, killing scores and forcing tens of thousands to flee.
The Muslim Rohingya are largely confined to camps and slapped with restrictions that rights groups have likened to apartheid.
Several complex ethnic conflicts are rumbling across Myanmar's borderlands, hampering efforts to build the country's economy after the end of junta rule.
But compared to the country's civil war-ravaged eastern and northern border states, Rakhine does not boast a significant rebel military presence.
In the last few years the Arakan Army, a small Buddhist militia which wants an independent homeland in the state, have fought sporadic battles with the military.
Despite their plight the Rohingya do not have a known militant faction fighting for them.
However many fear their continued plight could drive them to adopt more violent solutions.
In May armed attackers stormed a security post at a camp for Rohingya refugees in southern Bangladesh just across the border from Maungdaw.
In that attack a Bangladeshi camp commander was shot dead and the assailants made off with weapons.
Police at the time said the Rohingya themselves could be suspects.
In recent years Bangladeshi police have also alleged that Rohingya refugees are involved in criminal activities including human trafficking.
Any uptick in violence in Rakhine will be a major concern for the new civilian-led government of Aung San Suu Kyi.
She has asked former UN chief Kofi Annan to head a commission tasked with trying to heal sectarian divisions in the state.
The move was largely welcomed by Rohingya community leaders but drew ire from Buddhist nationalists.
Anti-Muslim sentiment still runs high in the impoverished region, fanned by hardline Buddhist nationalists who revile the Rohingya and are viscerally opposed to any move to grant them citizenship.
They insist the roughly one-million strong group are intruders from neighbouring Bangladesh, even though many can trace their ancestry in Myanmar back generations.