Myanmar troops have fired warning shots at a Chinese Red Cross aid convoy, the ruling junta says, underlining the challenge of delivering relief amid a civil war as aid groups call for better access to help survivors of a devastating earthquake.
The military has struggled to run Myanmar following its coup against the elected civilian government of Nobel laureate Aung San Suu Kyi in 2021, reducing the economy and basic services including health care to tatters after civil war broke out.
Junta spokesman Zaw Min Tun said the Chinese Red Cross had not informed authorities it was in a conflict zone on Tuesday night and a security team fired shots in the air after the convoy failed to stop.
China's foreign ministry said the aid team and supplies were safe and called on all parties in Myanmar to ensure the safety of rescuers.
"It's necessary to keep transportation routes for relief efforts open and unobstructed," spokesman Guo Jiakun told a news conference.
The firing came as the death toll from Friday's 7.7-magnitude quake rose to 2886, with 4639 injured, Myanmar state media said.
The rural parts of hard-hit Sagaing region were mostly under the control of armed groups fighting the military government, the International Crisis Group said.
"They will be among the most challenging for aid agencies to reach, given regime restrictions, a complex configuration of local administrations and control by armed resistance groups, and the persistent conflict," it said in a statement.
Even before the quake, the ICG said, information had been hard to gather from such areas because of a junta blackout of internet and mobile phone networks as part of the conflict.
Human Rights Watch urged the junta to allow unfettered access for humanitarian aid and lift curbs impeding aid agencies, saying donors should channel aid through independent groups rather than only junta authorities.
"Myanmar's junta cannot be trusted to respond to a disaster of this scale," Bryony Lau, deputy Asia director at Human Rights Watch, said in a report.
"Concerned governments and international agencies need to press the junta to allow full and immediate access to survivors, wherever they are."
The military has dismissed as misinformation accusations that it committed widespread atrocities as it fought against a multi-pronged rebellion that followed the coup.
Rebels accused the military of conducting air strikes even after the quake and on Tuesday a major rebel alliance declared a unilateral ceasefire to help relief efforts.
The United Nations said more than 28 million people were in the six regions affected by the quake, and it had $US12 million ($A19 million) in emergency funding for food, shelter, water, sanitation, mental health support and other services.
"The situation remains critical, with disrupted communications and road access hampering response efforts, particularly in Sagaing," the United Nations Office for Project Services said.
Australia announced a further $A6.5 million in humanitarian support for Myanmar, supplied "through thoroughly vetted international and local partners".
"We take proactive steps to ensure our assistance does not legitimise the military regime in Myanmar," Foreign Minister Penny Wong said.
In neighbouring Thailand, the death toll from the quake rose to 22 on Wednesday, with hundreds of buildings damaged.
A search for survivors in the rubble of a skyscraper under construction in the capital, Bangkok, entered its fifth day at the site, where 15 people died and 72 are missing.
The government is investigating the collapse and initial tests showed some steel samples from the site were substandard.
