The UN rights chief warned Tuesday Myanmar could be spiralling towards a "full-blown" Syrian-style conflict, after a two-month crackdown that a local monitoring group says has already claimed more than 700 lives.
Myanmar is in chaos and its economy has been paralysed since the military seized power from civilian leader Aung San Suu Kyi on February 1.
Warning of possible crimes against humanity, the United Nations High Commissioner for Human Rights Michelle Bachelet on Tuesday urged countries to take immediate action to push Myanmar's military to stop its "campaign of repression and slaughter of its people."
Daily rallies across Myanmar have been met with live rounds.
At least 710 civilians have been killed as of late Monday, including 50 children, according to a local monitoring group.
"I fear the situation in Myanmar is heading towards a full-blown conflict," Bachelet said in a statement.
"There are clear echoes of Syria in 2011," she warned, referring to the start of a civil war that over the past decade has killed nearly 400,000 people and forced more than six million to flee the country.
In recent weeks, several of Myanmar's ethnic rebel groups in some lawless border territories have stepped up attacks on the military and police, raising fears of a broader civil conflict.
The military has retaliated with air strikes, which the Free Burma Rangers -- a Christian aid group working in the area -- said had displaced more than 24,000 civilians in Karen state by Saturday.
The Rangers, which runs a health clinic in the state, said air strikes had killed at least 20 people and wounded more than 40.
The area is remote and communications are difficult, and AFP has not been able to independently verify the deaths.
Villagers in some areas were unable to prepare their rice crops because of fears the military would shell them in their fields, the aid group said.
"They are afraid they will have no rice harvest next fall," it said in a statement.
Military attacks sent a few thousand people fleeing into neighbouring Thailand in recent weeks, but most have returned to the Myanmar side of the border.
In Yangon, authorities are hunting those responsible for an underground newsletter titled "Molotov".
The publication was started by a group of young activists to fight ongoing internet outages and information suppression.
"The Molotov journal is illegally published," the state-run Global New Light of Myanmar said, adding that legal action would be taken against those involved.
Overnight, the junta announced a further 20 people were added to an arrest warrant list of 200 celebrities, including actors and singers, who are accused of spreading dissent against the military.
If convicted, they could face three years in jail.
With violence raging, many in coup-hit Myanmar are vowing to mark this week's Buddhist New Year festival with protests rather than the traditional water fights.
Some protesters say it would be disrespectful to enjoy the Thingyan holiday period when so many have lost their lives and around 3,000 people are detained.
Last year's festivities were also called off because of pandemic restrictions.
In parts of Yangon, Monywa and Bago, protesters observed Thingyan by painting pots with pro-democracy messages Tuesday and placing them on streets with flowers inside.
"Fight for democracy," a sign sticking out of a line of pots said in one Yangon township.
Others said, "Never give up".
"We are not having normal celebrations. Even though it is festival time right now, we cannot have fun. We will not be happy until this dictator is overthrown and we will revolt until then," a university student in Mandalay told AFP, speaking on condition of anonymity because of the danger of arrest.
Another protester named Ray in Yangon said the pots were a way to welcome the new year and "honour fallen heroes".
In Mandalay, people placed the pots and flowers on a golden stupa, with signs showing the three-fingered salute that has become a symbol of resistance.
Young people in cities nationwide continued to take to streets Tuesday, some marching with flowerpots.
Meanwhile, security forces found and defused a bomb beneath the Myaynigone bridge in Yangon on Tuesday morning, a police source said.
