Myanmar's military leader sought to justify last month's coup on the country's Armed Forces Day on Saturday, while local media reported security forces shot dead more than 90 protesters on the same day.
Armed Forces Day marks the start of resistance by independent power against the Imperial Japanese military in 1945.
Senior General Min Aung Hlaing said the coup was inevitable, and that the military is working hard to secure social and economic development for the nation and its people.
Prior to the ceremony, the military warned on state-run television that "bullets may go through the heads or backs of young people" who participate in riots.
Protests broke out early in the morning across the country, including in the largest city of Yangon and the second largest city of Mandalay following calls for demonstrations to coincide with the ceremony.
The online news service Myanmar Now says at least 91 people were killed nationwide by security forces on Saturday.
The military is stepping up moves to eliminate opposition and to crack down on protesters.