The clashes began Sunday night and spread to four townships, said state Attorney General Hla Thein.
The unrest between the majority Buddhists and the Rohingya minority began five months ago and 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.
Authorities have declared at state of emergency in two of the townships, with the state’s prime minister instructing that medical teams be accompanied by security personnel when they visit them.
The situation in the region has been tense since May when 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 third hung himself while in detention.
The violence spread across the northern part of the state, resulting in the destruction of thousands of homes and the deaths of dozens, according to the government.
The national government declared a state of emergency in Rakhine, bringing in the military to help restore order.
Hundreds of Rohingyas tried to cross the border into neighboring Bangladesh, but were turned back.
Bangladesh said it already has too many Rohingya refugees, estimating that about 300,000 live in the country.