"We will continue to fight for a government which is of the people, by the people, for the people,'' Ambassador Kyaw Moe Tun told the UN General Assembly in a surprise speech on Friday.
The rally drew hundreds of protesters, who sang and danced to the beat while holding up the three-fingered salute that has come to symbolise resistance to the coup.
Facebook said on Thursday they have removed all of the remaining military accounts with immediate effect.
About 3,000 teachers and students stood their ground a short distance from the barricades and barbed wire as the police watched impassively, holding riot shields and cradling rifles.
Youth-led protest gets musical as it kicks off in downtown Yangon
The official Facebook page of Myanmar's military was removed for "repeated violations", the social network said.
Rescue workers in Myanmar said two protesters have died after being fired on by security forces during an anti-junta rally in Mandalay.
Mya Thwet Thwet Khine had been demonstrating against the country's military coup, which happened on February 1. She was shot on February 9, two days before her 20th birthday.
Thousands of protesters rally near Yangon's central Sule pagoda in one of the biggest protests in Myanmar since the military coup on February 1.
The trial of Myanmar leader Aung San Suu Kyi took place in secret on Tuesday without her lawyer present, Human Rights Watch (HRW) has told Euronews.
The rebel music is aimed at encouraging youths to go against the military after the state coup earlier in February.
A near-total internet shutdown was reported on Sunday night, as mass protests against the military coup entered their second week.
Facebook has pledged to reduce the distribution of all content on Facebook pages and profiles run by the Myanmar Military “Tatmadaw”, as well as accounts linked to the armed forces spokesperson Brigadier-General Zaw Min Tun.
Street protests against last week's military coup continued on Wednesday.
Myanmar protests continue with police repression