Updated

A leading international rights group is accusing authorities in Myanmar, including senior Buddhist monks, of organizing a "campaign of ethnic cleansing" against the country's Rohingya Muslim minority.

Human Rights Watch on Monday described a series of bloody attacks last year that killed hundreds of people and forced 125,000 from their homes as crimes against humanity that the government of President Thein Sein has yet to punish.

The New York-based group says ethnic Rakhine nationalists from a powerful political party in western Rakhine state, along with senior Buddhist monks, encouraged coordinated attacks on Muslim neighborhoods.

The rights group says that while state security forces sometimes intervened to protect fleeing Muslims, more often they either stood idly by or participated directly in atrocities.

A Rakhine state government spokesman denied the allegations.