Two people were killed in the central town of Wetlet, the Myanmar Now news agency said, and two were killed in different towns in Shan State in the northeast, two media outlets reported. One person was also killed in the northern jade-mining town of Hpakant, the Kachin News Group reported.
Reuters could not verify the reports and a spokesman for the ruling junta did not answer calls seeking comment.
The protests are only one of the problems the generals have brought on with their Feb. 1 ouster of the elected government led by Nobel laureate Aung San Suu Kyi.
Wars with ethnic minority insurgents in remote frontier regions in the north and east have intensified significantly since the coup, displacing tens of thousands of civilians, according to United Nations estimates.
In some places civilians with crude weapons have battled security forces, while in central areas military and government facilities that have been secure for generations have been hit by rocket attacks and a wave of small, unexplained blasts.
There have been no claims of responsibility for the explosions.
Khit Thit media reported a blast outside a police barracks in Yangon early on Sunday. Vehicles were ablaze it said, but it gave no information on any casualties.
Later, it reported another blast in the city. A news portal in Shan State reported a blast outside the home of a prominent businessman.