Last Sunday, an angry Buddhist mob mistakenly believing the perpetrators of the rape were on board a bus beat 10 Muslim passengers to death.
Rioting then flared Friday when at least four Buddhists were killed in the state, with a second wave of violence in remote villages early Saturday.
Police and military units have been deployed to bring an end to the unrest, in which 17 people were also wounded and nearly 500 houses destroyed, according to official media.
Myanmar's Muslims -- of Indian, Chinese and Bangladeshi descent -- account for an estimated four percent of the roughly 60 million population in a country where experts say many people believe Buddhism forms an intrinsic part of national identity.
According to the UN, Myanmar has an estimated 750,000 Rohingya, living mainly in Rakhine. Another one million or more are thought to live in other countries.
Authorities in Bangladesh on Sunday said they were stepping up security along the border and in the refugee camps where around 300,000 Rohingya live.
President Thein Sein has overseen dramatic political reforms in Myanmar, which has begun to open to the outside world after decades of isolation.
The regime has also signed tentative ceasefire deals with a number of rebel groups in recent months as it seeks to draw a line under civil conflicts that have racked parts of the country since independence in 1948.
However, conflict continues to rage in the far north of the country.
