BANGKOK (Reuters) - The head of the U.N. refugee agency urged Myanmar on Friday to grant citizenship to the Rohingya, a stateless Muslim minority in the Asian country where sectarian violence has displaced tens of thousands since 2012.

UNHCR High Commissioner for Refugees Filippo Grandi gestures during a news conference at a hotel in Bangkok, Thailand, July 7, 2017. REUTERS/Athit Perawongmetha

On his first official visit to Southeast Asia, U.N. High Commissioner for Refugees Filippo Grandi this week met communities in the towns of Sittwe and Maungdaw in Myanmar’s Rakhine state, home to a large population of Rohingya Muslims.

He also met Aung San Suu Kyi, Myanmar’s de facto leader.

Rakhine State in west Myanmar has seen the most serious religious violence in predominantly Buddhist Myanmar since the military began to end its decades of strict rule, with hundreds of Rohingya Muslims killed and more than 140,000 people displaced there in communal unrest in 2012.

Tensions have risen again in recent days after village administrators were murdered and troops killed three people while clearing a Rohingya militant camp.

“It’s important to work on granting citizenship to the Muslim community, that has been deprived of citizenship for many years,” Grandi told reporters in Bangkok.

Myanmar’s government regards the approximately one million Rohingya as illegal migrants from neighboring Bangladesh and denies them citizenship, even though Rohingya families have lived there for generations.

Grandi also said that more investment was needed in the region.

“It is one of the poorest states in the Union of Myanmar and there’s an urgent need for development investments that must be inclusive of the two communities,” he said.

Last October, Rohingya insurgents launched deadly attacked on Myanmar guard posts near the Bangladesh border, provoking a military crackdown in which the United Nations says hundreds were killed, more than 1,000 homes burned and some 75,000 Rohingya fled to Bangladesh.

The United Nations has established a fact-finding mission to investigate crimes against humanity allegedly committed by Myanmar’s military during the counter-offensive.

Suu Kyi’s administration has rejected the allegations and opposes the mission.

In the latest unrest in the region, a Rohingya Muslim man was killed and six wounded when they were attacked by a mob of Rakhine Buddhists this week.

In Thailand, more than 102,000 refugees from Myanmar live in nine camps along the Thai-Myanmar border.

Most are members of the Karen ethnic minority who fled conflict in Myanmar over the past 30 years.

The Thai government was preparing to help about 200 camp residents to return to Myanmar in the near future, Grandi said, following the voluntary repatriation of 71 Myanmar refugees in October.

Grandi will fly to Bangladesh on Saturday.