The United Nations expert on human rights in Myanmar arrived in the country late Sunday, days after the UN voiced fears that efforts to end unrest in Rakhine state had turned into a crackdown on Muslims.
UN Special Rapporteur Tomas Ojea Quintana flew into the main city of Yangon for a visit set to include a trip to the restive western state as well as meetings with Myanmar's president and civil society.
It comes after a warning by UN human rights chief Navi Pillay that Muslim communities in Rakhine, particularly the Rohingya minority, were being targeted by security forces.
"We have been receiving a stream of reports from independent sources alleging discriminatory and arbitrary responses by security forces, and even their instigation of and involvement in clashes," she said in a statement Friday.
Quintana says that Myanmar has made "significant" progress on reforms under President Thein Sein, who came to power last year, but said the country faced "ongoing human rights challenges".
Violence between Buddhist ethnic Rakhine and Muslim Rohingya communities erupted in early June and have left at least 78 people dead and 70,000 homeless, according to official figures.
Unofficial estimates of the death toll were higher, the UN said.
Myanmar's government considers the estimated 800,000 Rohingya in the country to be foreigners while many citizens see them as illegal immigrants from neighbouring Bangladesh and view them with hostility.
Earlier this month, Thein Sein told the UN that refugee camps or deportation was the "solution" for the Rohingya, according to his official website.
Quintana is set to meet the Myanmar leader in the capital Naypyidaw on Friday following a trip to Rakhine state.
"We do not know what they will discuss. But of course the Rakhine state situation will be the main issue," a Myanmar government official told AFP, asking to remain anonymous.
Ten aid organisation staff, including some from the UN, were detained in Rakhine in the wake of the unrest, according to a situation bulletin by the UN Office for the Coordination of Humanitarian Affairs (OCHA) earlier this month. They are thought to have appeared in court in mid-July.
Quintana's visit is due to last until August 4.