President Thein Sein has declared a state of emergency in western Myanmar following deadly clashes between local Buddhists and Muslims.
State television on Sunday said a dusk to dawn curfew had been imposed in the Rakhine state capital of Sittwe and three other townships. Public gatherings of more than five persons were also banned.
The move follows rioting on Friday in two other areas of Rakhine state that, according to state media, left at least seven people dead and 17 wounded, and saw hundreds of houses burned down.
Official accounts blamed the rioting in Maungdaw and Buthidaung townships on 1,000 "terrorists", but residents' accounts made clear they were Muslims, apparently retaliating for the June 3 lynching of 10 Muslims by a crowd of 300 Buddhists.
The mob had been inflamed by the rape and murder last month of a Buddhist girl, allegedly by three Muslim men.
The violence reflects long-standing tensions in Rakhine state between Buddhist residents and the region's Muslim minority, who call themselves Rohingya, many of whom are considered to be illegal settlers from neighbouring Bangladesh.
The Rohingya are a Muslim ethnic group from the northern Rakhine state of western Myanmar, formerly known as Arakan state.
Their history dates to the early 7th century, when Arab Muslim traders settled in the area.
They are physically, linguistically and culturally similar to South Asians, especially Bengali people.
According to Amnesty International, they suffer from human rights violations under the Myanmar military government, and many have fled to neighbouring Bangladesh as a result.
The vast majority of them have effectively been denied Myanmar citizenship.
In 1978 an estimated 200,000 Rohingyas fled to Bangladesh.
Approximately 20,000 Rohingya are living in UN refugee camps in Bangladesh.
Although the root of the problem is localised, there is fear that the trouble could spread elsewhere because the split also runs along religious lines.
The new curfews were imposed in reaction to new clashes on Saturday and Sunday outside Friday's trouble spots, where order was said to have been restored.
"Some houses were set on fire by the Muslims today in Sittwe and four Rakhine villagers arrived at the hospital with knife wounds," said Nu Nu Tha, a resident of Sittwe contacted by The Associated Press news agency by phone.
"Almost all shops are closed and people live in fear that the Muslims might attack the Rakhine population. I am very scared and I have sent my children to Yangon by plane," Nu Nu Tha said.
Shops in Sittwe were closed and the busy port city was unusually quiet on Sunday, according to residents.
Army troops had been deployed on Friday in Maungdaw and Buthidaung to help police keep order, and security officials were reported to have fired shots to quell the violence, in addition to imposing a curfew.
In Yangon on Sunday, Buddhist monks and people from Rakhine state - about 500 in all - went to the Shwedagon Pagoda, Myanmar's most revered Buddhist shrine, to say prayers for the murdered girl and those killed in the clashes.
The amount of information about Friday's incident released by state media in a timely fashion was nearly unprecedented, although still far from comprehensive.
Under the previous military government, such incidents usually went unreported or were referred to only in brief, cryptic fashion.
The Rohingya are descended from South Asians and speak a regional dialect of Bengali. Most are stateless, recognised as citizens neither by Myanmar nor neighbouring Bangladesh. The UN's refugee agency estimates there are about 800,000 of them in three districts of Rakhine state bordering Bangladesh.