Myanmar is holding an election widely condemned as a sham, with key opposition parties dissolved and many of their leaders imprisoned.
A significant portion of the country is unable or unwilling to participate due to a widespread civil conflict.
The military government, which seized power in a coup nearly five years ago, is conducting the phased vote.
The takeover sparked massive opposition that has since escalated into a devastating civil war.
Observers suggest the junta, with support from China, is attempting to legitimise and consolidate its power while searching for a way out of the ongoing military stalemate.
Authorities have charged more than 200 people under a new law for disrupting or criticising the polls.
The legislation carries severe punishments, which can include the death penalty.
Polling began on Sunday amid heightened violence, with reports of explosions and airstrikes in multiple regions.
In the Mandalay region, the chief minister confirmed a rocket attack on an uninhabited house in the early hours of Sunday injured three people, one of them seriously.
Separately, a series of explosions late on Saturday damaged more than ten houses in Myawaddy township near the Thai border.
A local resident reported that a child was killed and three others were taken to hospital in an emergency condition following that attack.