Myanmar has deployed hundreds of troops in the volatile Rakhine state amid concerns by the United Nations that the development would pave the way for more violence in the region.

Rakhine has been gripped by violence since October last year when gunmen attacked police posts, sparking a bloody military crackdown that the UN believes may amount to ethnic cleansing of the Muslim minority Rohingya.

More than 70,000 Rohingya villagers fled across the border to Bangladesh, carrying with them stories of systematic rape, murder and arson at the hands of soldiers.

The major part of the military campaign ended several months ago, but fear continues to stalk the region amid sporadic bouts of violence.

Officers said Saturday that the government had deployed a fresh batch of troops after a recent spate of murders. They said soldiers have been sent to a mountainous area where a band of gunmen is actively training.

A senior border guard said the deployment was ordered to protect other ethnic groups in the remote area. The government has accused insurgents of murdering and abducting dozens of villagers and perceived collaborators with the state.

“We have to increase security operations because the security situation has worsened – some Muslims and Buddhists have been killed by the insurgents,” Rakhine State police chief Colonel Sein Lwin told Reuters.

The military spokesman and a spokesman for Myanmar’s de facto leader, Aung San Suu Kyi, were not immediately available for comment.

State media also reported that the government had imposed new curfews, to be set “in necessary areas” as the army beefs up its “clearance operations”.

Reports of an army battalion being flown into Rakhine to boost security were met with criticism on Friday by UN special rapporteur Yanghee Lee, who warned the development was “a cause for major concern”.

“The government must ensure that security forces exercise restraint in all circumstances and respect human rights in addressing the security situation in Rakhine State,” she said in a statement issued in Geneva.

United Nations investigators who interviewed some of the nearly 75,000 people who fled to neighboring Bangladesh last year said troops probably committed crimes against humanity.

The government rejects the allegations and has refused to cooperate with a UN fact-finding mission to look into abuses in Myanmar. It has dismissed the allegations and vowed to block a UN probe into the violence.

Regional rights body ASEAN Parliamentarians for Human Rights voiced concern about the increased number of troops in Rakhine.

“Aung San Suu Kyi should call on all parties, including the Myanmar army, to take steps to de-escalate conflict in northern Rakhine State, rather than exacerbate it,” a member of its board, Eva Kusuma Sundari, said in a statement.

A Rohingya villager told AFP his community feared a repeat of last year’s crackdown.

“Some Muslim villages in Rathidaung dare not to go outside,” said Hasumyar, who only gave his first name and lives in a township that has been placed under curfew.

Buddhist-majority Myanmar has long faced criticism for its treatment of the more than one million Rohingya, who are denied citizenship and struggle to access basic services.

The minority group are widely reviled as illegal migrants from Bangladesh, despite having lived in the area for generations.