"I deplore the loss of life in Du Chee Yar Tan and call on the authorities to carry out a full, prompt and impartial investigation and ensure that victims and their families receive justice," High Commissioner for Human Rights Navi Pillay said in a statement from the U.N. offices in Geneva.
A spokesman for Myanmar President
The government "strongly objects" to the accusations, spokesman Ye Htut said, according to the Associated Press. He said the reported death toll and reports of revenge killings were "totally wrong."
Rakhine state is home to at least 80% of the country's million-strong population of stateless Rohingyas, many of them natives of Myanmar, also known as Burma, but are regarded as refugees and widely persecuted by the state and the Buddhist majority.
Journalists are barred from northern Rakhine, and humanitarian aid agencies also have limited access, making it difficult to confirm details of the violence that has persistently afflicted the area.
Pillay said in her statement that the world body had received credible reports that eight Rohingya men were attacked and killed Jan. 9 in the village of Du Chee Yar Tan. An additional 40 Muslims, including women and children, were slain in a second wave of violence four days later, apparently in retaliation for the disappearance and presumed killing of a local policeman, the statement said.
Authorities in the area were also arresting Rohingyas and prompting concerns by human rights advocates that they were being mistreated, Pillay said.
"I urge the government to ensure that the rights of anyone detained are fully respected," Pillay said. "I also encourage the Government to provide humanitarian actors with access to the village to provide any assistance needed to the local population."
If confirmed, the massacre this month would bring to about 280 the number of Rohingya Muslims killed since sectarian violence flared two years ago in Rakhine.
The Fortify Rights advocacy group echoed the U.N. concerns, appealing to the local and national governments to provide "unfettered humanitarian access" to the region.
"The authorities can't defensibly speak the language of human rights reform while sealing off the site of yet another massacre in Rakhine state," the group's executive director, Matthew Smith, said in a statement.
He referred to the strides Myanmar has made in winding down the military dictatorship that ruled for decades. Political prisoners have been released, oppressed activists like
The United Nations considers the Rohingya one of the most mistreated minorities in the world. In Myanmar, they are not only denied citizenship but must get permission from the government to marry. Rohingya couples, unlike those of other ethnic and religious groups, are allowed to have no more than two children.