Massive protests erupted in major cities and towns in Myanmar on Sunday to condemn the killing of two protesters at the hands of security forces, and to demonstrate their outrage against the Feb. 1 military coup.

Police and security forces opened fire on demonstrators in Mandalay, the country's second-largest city, on Saturday, killing two protesters, including a teenage boy who volunteered to help the injured.

A volunteer medic told Anadolu Agency that tens of thousands of people have joined a protest sit-in, blocking major intersections in Mandalay. “It is like a sea of people," he said on the condition of anonymity.

Activist Than Myat Soe alleged that the security forces had “used live rounds of ammunition on the protesters, which is why there were casualties."

Dissidents and activists have called for major rallies across the country on Monday to demonstrate their rejection of the ruling military junta.

Shops in Yangon were seen putting notices that they would remain closed for a day to join the protests.

A video footage of protesters performing a ritual in Yangon’s Sanchaung township, praying for the failure of the dictatorship, has also went viral on social media.

At least three protesters have been killed during the ongoing anti-coup demonstrations since the coup d'état.

A 20-year-old girl protester, who was shot in the head in the administrative capital Nay Pyi Taw and succumbed her injuries on Friday, became the country's first victim.

A 30-year-old man was also killed on Saturday in Yangon's Shwe Pyi Thar township after police shot him in the head as he tried to prevent the police vehicle from entering his residential area./aa