Several buildings in Rohingya villages in western Myanmar have been torched in the on-going crises in the area.
Northern Rakhine, which is home to the Muslim Rohingya minority and borders Bangladesh, has been under military lockdown ever since surprise raids on border posts left nine police dead last month.
Soldiers have killed several dozen people and arrested scores in their hunt for the attackers, who the government says are radicalised Rohingya militants with links to overseas Islamists.
Fresh fighting flared on Saturday with two soldiers and six attackers killed, according to the military who said they brought in helicopter gunships to repel an ambush.
The crisis and reports of grave rights abuses being carried out in tandem with the security crackdown have piled international pressure on Myanmar's new civilian government and raised questions about its ability to control its military.
Authorities have heavily restricted access to the area, making it difficult to independently verify government reports or accusations of army abuse.
New satellite images released by Human Rights Watch show what the group said was evidence of mass arson attacks against Rohingya villages.
Their analysis showed more than 400 buildings torched in three Rohingya villages where the fighting has been taking place.
The group said active fires and burn scars showed that most of the destruction was caused by arson. The latest images were taken on 10 November.
Brad Adams, the group's Asia director, said the new photos showed "widespread destruction" that was "greater than we first thought".
"Burmese authorities should promptly establish a UN-assisted investigation as a first step toward ensuring justice and security for the victims," he said in a statement.
The resurgence of violence in western Rakhine has deepened and complicated a crisis that already posed a critical challenge to the new administration led by democracy activist Aung San Suu Kyi.
The state has sizzled with religious tension ever since waves of violence between the majority Buddhist population and the Muslim Rohingya left more than 200 dead in 2012.
More than 100,000 people, mostly Rohingya, were pushed into displacement camps by the bloodshed and have languished there ever since.
Rights groups say they face apartheid-like restrictions on movement and have repeatedly called on Suu Kyi to carve out a solution.
But Buddhist nationalists at home viciously oppose any move to grant them citizenship, claiming the Rohingya are illegal immigrants from Bangladesh despite their long roots in the country.
The military and government have rejected allegations that troops have burned Rohingya villages, accusing insurgents of lighting the fires.
On Saturday evening, Rohingya activists uploaded a graphic video showing the corpses of eight people dressed in civilian clothes, including a small baby.
The video's shooter, speaking in Rohingya, said the victims died that day near Dar Gyi Zar village, with some showing bullet wounds.
It was not possible to verify the authenticity of the footage.