One of several bombs targeting government offices and other places in Myanmar's troubled Rakhine state exploded on Saturday morning, injuring a police officer, authorities said.

In all, three bombs exploded and three unexploded devices were seized in Sittwe, the state capital. One of the explosions was in front of a high-ranking government official's residence, state police officer Aung Myat Moe said.

"There were three bomb explosions around 4am this morning where one policeman was slightly injured and we are still investigating crime scenes," he said.

Last month, local police fired at protesters in the ancient city of Mrauk-U, killing at least seven Rakhine Buddhists and injuring a dozen. A township administrator was later found slain in his car by the side of the road.

Communal violence in Sittwe in 2012 displaced more than 120,000 Rohingya Muslims now confined to camps outside of the city, where most Rakhine Buddhists remain.

About 700,000 Rohingya have fled northern Rakhine towns and villages since last August to escape a military crackdown.