Around 400 people, most of them Rohingya Muslims have died in communal violence searing through Myanmar's Rakhine state, the army chief's office said on Friday, with tens of thousands forced to flee across the border into Bangladesh.
A further 20,000 Rohingya have massed along the Bangladeshi frontier, while scores of desperate people have drowned attempting to cross the Naf, a border river, in makeshift boats.
Reports of massacres and the systematic torching of villages by security forces — as well as by militants — have further amplified tensions, raising fears that communal violence in Rakhine is spinning out of control.
"Until August 30, a large number of terrorists carried out 52 waves of attacks on security forces ... In those attacks, 370 bodies of terrorists were found and nione other captured alive," a statement posted on the Facebook page of Commander-in-Chief Min Aung Hlaing's office said on Friday.
Fifteen security forces and 14 civilians have also died in eight days of fighting, it added.
It was unclear if the deaths of 78 militants killed last Friday in raids on police posts that sparked the current round of violence had been included in the toll.
Either way, it is the bloodiest chapter yet in a bitter five-year crisis that has torn apart Rakhine state along ethnic and religious lines, displaced the Rohingya in huge numbers and heaped international condemnation on Myanmar's army and the government of Aung San Suu Kyi.
Rights groups say the true toll is likely much higher.
Fortify Rights, an NGO with a focus on Myanmar, said eyewitnesses alleged mobs shot and hacked down Rohingya villagers, including children in a five-hour "killing spree" in the village of Chut Pyin in Rathedaung township on Sunday afternoon.
The allegations could not be independently verified by AFP as the area is off-limits to reporters.
Myanmar's Information Committee appeared earlier this week to confirm a major security operation took place around the village on Sunday afternoon as a patrol clashed with scores of Rohingya militants.
But it is hard to pin down exact details amid the claims and counter-claims of abuses and violence by the opposing sides.
Desperate to reach Bangladesh, thousands of Rohingya have taken to makeshift boats in an effort to cross the Naf river which separates the two countries.
The UN says at least 27,000 have made it across.
But others died trying to flee burning villages.
Eighteen bodies washed ashore in Bangladesh today, a border official said, lifting the toll over the last two days to 41.