Activists called for what they dubbed a bloody paint strike and people responded with red smeared on roads, on signs outside government offices and on T-shirts, according to pictures posted on social media.
Some people marched with signs calling for the release of the leader of the ousted government, Nobel laureate Aung San Suu Kyi. She has been detained since the Feb. 1 coup on various charges including violating an official secrets act that could see her imprisoned for 14 years.
Her lawyers have denied the charges against her.
“Please save our leader - future - hope,” read a sign with a picture of Suu Kyi held by a young woman marching in the second city of Mandalay, according to a picture published by the Mizzima news service, Reuters reported.
The five-day New Year holiday, known as Thingyan, began on Tuesday but pro-democracy activists cancelled the usual festivities, which include high-spirited water throwing in the streets, to focus on their campaign against the generals who seized power.
The military says the protests are petering out. Activists have planned different shows of defiance every day over the holiday, which ends on Saturday.
The coup has plunged Myanmar into crisis after 10 years of tentative steps toward democracy with daily protests and strikes by workers in many sectors that have brought the economy to a standstill.
The United Nations human rights office said on Tuesday it feared that the military clampdown on the protests risked escalating into a civil conflict like that seen in Syria and appealed for a halt to the “slaughter”.
A Myanmar activist group, the Assistance Association for Political Prisoners, says the security forces have killed 710 protesters since the ouster of Suu Kyi’s government.
The coup has also rekindled hostilities in old wars between the military and ethnic minority forces fighting for autonomy in border regions.
Government forces suffered heavy casualties in an assault on ethnic Kachin forces in the north, the Myanmar Now media group reported.
A spokesman for the junta could not be reached for comment.