More than 1,000 homes have been razed in Rohingya villages in northwest Myanmar during a military lockdown there, according to analysis of satellite images from Human Rights Watch (HRW) released yesterday that fly in the face of government denials.

HRW reported that by using satellite imagery it had identified 820 more structures destroyed in five Rohingya villages between Nov. 10 and Nov. 18.

In total, the rights group said 1,250 buildings had been destroyed during the military lockdown.

Troops have poured into a strip of land along the Bangladesh border, an area which is largely home to the stateless Muslim Rohingya minority, since a series of coordinated and deadly attacks on police border posts last month.

Up to 30,000 people have been displaced by the ensuing violence, according to the U.N., half of them over a two-day period when dozens died after the military brought in helicopter gunships.

Security forces have killed almost 70 people and arrested some 400 since the lockdown began six weeks ago, according to state media reports, but activists say the number could be far higher.

Witnesses and activists have reported troops killing Rohingya, raping women and looting and burning their houses. The government has refused to allow in international observers to carry out a full investigation.

Myanmar's 1.1 million Rohingya Muslims are denied citizenship, with many of the country's majority Buddhists regarding them as illegal immigrants from Bangladesh. More than 100 people died in 2012 in clashes between the majority Buddhist population and the Rohingya, and tens of thousands of them were driven into displacement camps. The resurgence of violence in Rakhine poses a critical challenge to Suu Kyi's administration seven months after it took power.