Myanmar officials, backed by extremist Buddhist monks, may have had a role in violence against Rohingya Muslims in western Rakhine State, according to a new report by a US-based human rights group.

Human Rights Watch accused security forces and community leaders of “coordinated attacks” against the minority Muslim group in a campaign of “ethnic cleansing” that has displaced more than 125,000 Rohingyas as violence razed hundreds of Muslim houses and temples to the ground. More than 180 from both sides of the conflict were killed.

The report accused the Myanmar government of not intervening to stop the violence or punish those behind the attacks. Although security forces were sent in, witnesses described how they “stood aside during attacks or directly supported the assailants, committing killings and other abuses,” the report said.

The government’s failure to protect Muslims has also emboldened others to instigate attacks elsewhere and has “helped sparked radical anti-Muslim activity,” Phil Robertson, deputy Asia director at HRW, told Reuters.

“The absence of accountability against those to blame lends credence to allegations that this was a government-appointed campaign of ethnic cleaning in which crimes against humanity was committed,” the report stated.

The report comes as the European Union voted to lift all sanctions on Myanmar, except an arms embargo, in recognition of reforms in the country. However, concerns remain over Myanmar’s poor human rights record.