The military junta warned it was prepared to use lethal force against rallies inciting "riot and anarchy".
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.
"Why are they using so much force? They pushed us violently. Why did they do that?" said one young protester who had argued with an officer.
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.
Hundreds of anti-coup protesters gathered at the Hledan junction in Yangon on Tuesday, after Myanmar's generals imposed a second straight overnight internet shutdown.
A near-total internet shutdown was reported on Sunday night, as mass protests against the military coup entered their second week.
Demonstrators called for civil disobedience as mass street protests against military rule in Myanmar entered their second week.
Thousands of protesters in Myanmar have defied a ban on gatherings by the military who ousted the elected government two weeks ago.
Haitian police fire tear gas on hundreds of protesters
Myanmar protests continue with police repression
Protests against the military coup in Myanmar continued into Tuesday, despite new rules making demonstrations illegal.
Myanmar saw its largest anti-coup protests yet on Saturday with young demonstrators spilling on to the streets to denounce the new military regime, despite a nationwide internet blackout.
UN Security-General Antonio Guterres said everything possible would be done to mobilise international pressure "to make sure that this coup fails".
Events in Mali could have a ripple effect across West Africa, and heighten issues such as poverty and terrorism.