Myanmar security forces killed at least 12 people, witnesses and media reported, as the acting leader of a civilian parallel government vowed in a first public address on Saturday to pursue a “revolution” to overturn the February 1 military coup.

Five people were shot dead and several injured when police opened fire on a sit-in protest in Mandalay, Myanmar’s second-biggest city, witnesses told Reuters.

Another person was killed in the central town of Pyay and two died in police firing in the commercial capital Yangon, where three were also killed overnight, domestic media reported.

“They are acting like they are in a war zone, with unarmed people,” said Mandalay-based activist Myat Thu. He said the dead included a 13-year-old child.

Si Thu Tun, another protester, said he saw two people shot, including a Buddhist monk. “One of them was hit in the pubic bone, another was shot to death terribly,” he said.

In Pyay, a witness said security forces initially stopped an ambulance from reaching those who were injured, leading to one death.

A truck driver in Chauk, a town in the central Magwe region, also died after being shot in the chest by police, a family friend said.

More than 70 people have been killed in Myanmar in widespread protests against the military’s seizure of power, the Assistance Association for Political Prisoners advocacy group has said.

The deaths came as the leaders of the US, India, Australia and Japan vowed to work together to restore democracy in the southeast Asian nation and the acting leader of the country’s ousted civilian government addressed the public for the first time.

Mahn Win Khaing Than, who is in hiding along with most senior officials from the ruling National League for Democracy Party, addressed the public via Facebook, saying, “This is the darkest moment of the nation and the moment that the dawn is close”.

He was appointed acting vice-president by representatives of Myanmar’s ousted lawmakers, the Committee for Representing Pyidaungsu Hluttaw, which is pushing for recognition as the rightful government.

The group has announced its intention to create a federal democracy and leaders have been meeting representatives of Myanmar’s largest ethnic organisations, which already control vast swathes of territory across the country.