The New York-based group said in a statement that satellite images taken on Nov 10, 17 and 18 showed 820 destroyed buildings, bringing the total number it says it has documented to 1,250.
Myanmar government has rejected allegations by residents and rights groups that soldiers have burnt houses and killed civilians during the military operation in Rakhine.
The army has declared the Muslim Rohingya-majority northern Rakhine as an "operations zone", where it claims to be battling Islamist insurgents.
The government has blocked international journalists from visiting the area.
Authorities have confirmed 86 deaths and said that 69 of them were suspected militants. Rights groups claim the number is much higher.
Hundreds of Rohingyas are trying to cross the border into Bangladesh amid escalating violence.
The Myanmar government has denied the Rohingya flight, but Bangladesh border guards have pushed hundreds of them back to their country in the last few days.
The 1.1 million Rohingyas are seen as illegal immigrants from Bangladesh by many of the country's majority Buddhists.
They are denied citizenship and face severe restrictions on their travel.
Up to 30,000 people are now estimated to be displaced and thousands more affected by the recent fighting, the UN has said.
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