Violence denounced by West
At the tourist spot of Inle Lake, people including Buddhist monks took to a flotilla of boats holding aloft portraits of Suu Kyi and signs saying “military coup — end.”
The more than two weeks of protests had been largely peaceful until Saturday, unlike previous episodes of opposition during nearly half a century of direct military rule to 2011.
The violence looked unlikely to end the agitation.
“The number of people will increase ... We won't stop,” protester Yin Nyein Hmway said in Yangon.
Several Western countries that have condemned the coup decried the violence against protesters.
U.S. State Department spokesman Ned Price said the United States was “deeply concerned.” France, Singapore, Britain and Germany also condemned the violence and UN Secretary-General Antonio Guterres said lethal force was unacceptable.
Sunday's Foreign Ministry statement reiterated the junta's stance that the takeover was constitutional and said remarks by some embassies and foreign countries “are tantamount to flagrant interference in internal affairs of Myanmar.”
Military spokesman Zaw Min Tun has not responded to attempts by Reuters to contact him.
The trouble in Mandalay began with confrontations between security forces and striking shipyard workers.
Video clips on social media showed members of the security forces firing at protesters.
UN Special Rapporteur for Myanmar Tom Andrews said he was horrified by the deaths of the two, one of them a teenage boy.
“From water cannons to rubber bullets to tear gas and now hardened troops firing point blank at peaceful protesters. This madness must end, now,” he said on Twitter.
The state-run Global New Light of Myanmar newspaper said the strikers sabotaged boats at the city's river port and attacked police with sticks, knives and catapults. Eight officers and several soldiers were injured, it said.
“Some of the aggressive protesters were also injured due to the security measures conducted by the security force in accordance with the law,” the newspaper said without mentioning the deaths.
Suu Kyi's National League for Democracy (NLD) called the violence by security forces in Mandalay a crime against humanity.
In an announcement on state-owned media MRTV late on Sunday, authorities said that by planning a big demonstration on Monday, protesters were inciting anarchy and pushing young people toward a path of confrontation “where they will suffer the loss of life.”
A young female protester, Mya Thwate Khaing, became the first death among the demonstrators on Friday. She was shot in the head in the capital, Naypyitaw.