Several people, including a regional security minister, a fireman and a monk who were trying to discourage the violence, were injured after being struck by objects flung by slingshots carried by some of the hundreds of Buddhist rioters Sunday in Htan Gone village, Radio Free Asia reported.
Angry people attacked a mosque and prevented fire engines from reaching dozens of torched homes and shops, officials said.
Police fired warning shots to control the crowd and held about a dozen suspected arsonists before bringing the situation under control.
Kanbalu township police said more than 30 Muslim houses and shops were gutted.
There was no word on the number of men involved in the reported assault on the woman, or on her condition. A crowd mobbed a police station in Htan Gone, demanding one suspect held on suspicion in the alleged assault be turned over to the group, Radio Free Asia said.
Myint Naing, an opposition parliamentarian and doctor from Kanbalu, blamed authorities for the violence, citing a lack of security measures to tamp down the situation quickly.
"It shouldn't have happened," said Naing, a lawmaker from opposition leader Aung San Suu Kyi's National League for Democracy.