At least four people have been killed and more than 1,000 houses burned down since the clashes began on Sunday.
Police have deployed reinforcements in the townships of Min Bya and Mrauk Oo, where curfews are now in effect.
The BBC Burmese Service says at least one person was killed in fighting in Mrauk Oo on Wednesday.
Rakhine state spokesman Myo Thant said the fighting had now spread to the townships of Kyauk Phyu and Myebon, south of the state capital Sittwe.
"Houses are burning and clashes between the two communities are ongoing," he said.
"The most important thing is to put out the fires. We are trying to control the situation."
Background: Burma unrest
What sparked the violence in June?The rape and murder of a young Buddhist woman in Rakhine in May set off a chain of deadly religious clashes.
Why was a state of emergency declared?
A state of emergency allows the introduction of martial law, which means the military can take over administrative control of the region.
Who are the Rohingyas?
The United Nations describes Rohingya as a persecuted religious and linguistic minority from western Burma. The Burmese government, on the other hand, says they are relatively recent migrants from the Indian sub-continent. Neighbouring Bangladesh already hosts several hundred thousand refugees from Burma and says it cannot take any more.
In June, 90 people were killed as religious clashes spread across the state.
The houses of both Buddhists and Muslims were burnt down and thousands of people fled.
It is unclear what prompted the latest clashes. Muslims and Rakhine Buddhists blame each other for the violence.
The two communities are now almost completely segregated in towns such as Sittwe, where the Rakhine are able to roam freely while the Rohingya are mostly confined to a series of camps.
Muslims throughout Burma have abandoned plans to celebrate the festival of Eid al-Adha because of the violence.
In August Burma set up a commission to investigate the violence between Buddhists and Muslims in the west of the country. Authorities earlier rejected a UN-led inquiry.
BY:BBC










