Mandalay/Bangkok: Human Rights Watch on Sunday condemned the crackdown in Myanmar by security forces as "outrageous and unacceptable".
Phil Robertson, the Deputy Asia Director of the New York-based organisation, said the world is watching the military junta and added that they should be "held accountable" for their "unlawful acts".
The security forces made mass arrests and appeared to use lethal force on Sunday as they intensified their efforts to break up protests a month after the military staged a coup.
There were reports of gunfire as police in Yangon, the country's biggest city, fired tear gas and water cannon while trying to clear the streets of demonstrators demanding that the elected government of Aung San Suu Kyi be restored to power.
Read: Myanmar deploys snipers against protesters
Photos of shell casings from live ammunition used in assault rifles were posted on social media.
Reports on social media identified one young man believed to have been killed in Yangon.
His body was shown in photos and videos lying on a sidewalk until other protesters were able to carry him away.
A violent crackdown also occurred in Dawei, a much smaller city in southeastern Myanmar, where local media reported that at least three people were killed during a protest march.
Read: Myanmar sacks its UN envoy after anti-coup speech
The fatalities could not immediately be independently confirmed, though photos posted on social media showed a wounded man in the care of medical personnel, and later laid out in a bed under a blanket with flowers placed on top.
Confirming reports of protesters' deaths has been difficult amid the chaos and general lack of news from official sources.
Prior to Sunday, there had been eight confirmed reports of killings linked to the army's takeover, according to the independent Assistance Association of Political Prisoners.
Read: Police fire tear gas at protesters in Myanmar
The Feb. 1 coup reversed years of slow progress toward democracy after five decades of military rule.
Suu Kyi's National League for Democracy party would have been installed for a second five-year term in office, but the army blocked Parliament from convening and detained her and President Win Myint, as well as other top members of Suu Kyi's government.
AP
