UNITED NATIONS, Jan. 17 (Xinhua) -- The United Nations is "following with concern" reports of deadly violence involving Buddhists in Myanmar's Rakhine State, home to more than 1 million Rohingyas, of which at least 640,000 have fled to neighboring Bangladesh in the face of ethno-religiously based attacks, said an UN official Wednesday.

Media reports said seven Buddhist demonstrators were shot dead by police in Mrauk U in northern Rakhine and another 12 people were injured during a celebration in the ancient Buddhist kingdom.

"The United Nations in Myanmar is following with concern the reports of violent clashes between the police and protesters in Mrauk U," said Chief UN Spokesman Stephane Dujarric.

"The UN Office deplores the loss of life and injuries that have been reported," he told reporters. "It urges respect for the rights to peaceful assembly and freedom of expression, and calls for the security forces and demonstrators to act with restraint and to avoid further violence."

"The UN Office urges authorities to investigate any disproportionate use of force or other illegal actions that may have occurred in relation to this incident," he said.

Following a deadly rebel attack against police posts in Rakhine State last August, Rohingyas began pouring into Bangladesh, claiming they were being attacked by the government and vigilante forces who also burned their villages, raped and killed, while Myanmar's military has acquitted itself of any atrocities.

Most of the Muslim refugees who fled to Bangladesh were from northern Rakhine State.