(CNN) -- Sectarian violence has sparked a "serious" human rights situation in western Myanmar, a U.N. envoy said.
Tomas Quintana, the U.N.'s human rights rapporteur for Myanmar, called for an independent investigation into allegations that authorities are using excessive force and committing other human rights violations while trying to restore order in Rakhine state.
"While I am in no position to be able to verify these allegations at this point in time, they are of grave concern," Quintana said Saturday after completing a six-day visit to the country that included a trip to the western state, where a surge in sectarian violence between Buddhists and Muslims in recent months has left dozens dead and displaced thousands.
Rakhine is home to the Rohingya, an ethnic Muslim minority who say they have been persecuted the Myanmar military during its decades of authoritarian rule.
On Saturday, Quintana said an investigation in Rakhine is important to guarantee accountability.
"Reconciliation will not be possible without this, and exaggerations and distortions will fill the vacuum to further fuel distrust and tensions between communities," he said.
Quintana also called for the release of six United Nations staff members in prison who were detained "in connection with events" in the state.
"I am of the view that the charges against them are unfounded and that their due process rights have been denied," he said.
Their detention comes at a time that Myanmar has released hundreds of political prisoners, including opposition leader Aung San Suu Kyi, and instituted a series of political reforms after decades of repressive military rule. Western governments have responded to the efforts by easing sanctions on the country.
Violence between Buddhists and Muslims erupted in Rakhine in June, after police detained three Muslim men in relation to the rape and killing of a Buddhist woman. Two of the men were sentenced to death, the government-run newspaper New Light of Myanmar reported on its website. A third man hanged himself while in detention on June 9.
News of the crime appears to have motivated several hundred people to attack a bus in Rakhine in early June, killing 10 Muslims who were on board.
Violence between Buddhists and Muslims then spread across the northern part of the state, resulting in the destruction of thousands of homes and the deaths of about 50 people, according to the government.
The national government declared a state of emergency in Rakhine, bringing in the military to help restore order.
The unrest has tested the efforts of President Thein Sein's administration to seek reconciliation with Myanmar's different ethnic groups and move the country toward more democratic governance.
CNN's Jethro Mullen contributed to this report.