Myanmar's government admitted its "weak" response to floods inundating huge areas of the country had hampered evacuation efforts as officials warned that swollen rivers were threatening new areas.
Flash floods and landslides caused by unusually heavy monsoon rains have claimed at least 46 lives and affected some 215,000 people, submerging massive areas of the country, while relentless downpours have lashed much of south and southeast Asia.
Criticism has mounted on social media with the government, which is led by former generals, accused of underplaying the scale of the disaster and not being quick enough to warn of the looming crisis.
It prompted a rare concession by the quasi-civilian government.
"The government's weak response to the disaster led to misunderstandings about evacuation efforts," the state newspaper Global New Light of Myanmar reported, citing government spokesman Ye Htut.
Myanmar has designated four states and regions -- Rakhine, Chin, Sagaing and Magway -- as "natural disaster" areas, warning that flooding has begun to spread southwards as water drains into swollen rivers.
Soldiers loaded aid into helicopters in the Rakhine state capital Sittwe early Tuesday as rescuers battled to reach isolated villages hit by torrential rains and a cyclone that barrelled through the Bay of Bengal last week.
The full impact of the flooding on Rakhine State is yet to emerge.
A Sittwe police officer said 37 people had died in the state alone, indicating the final national toll could surge. "Seven people are still missing," he added, requesting anonymity as he is not authorised to speak to the press.
The United Nations said more than 30,000 people have been evacuated, but information remains patchy with roads damaged or inundated, phone lines down and electricity cut to large areas.
Strong winds also damaged buildings in exposed coastal camps in Sittwe hosting about 140,000 people, mainly Rohingya Muslims, who were displaced following deadly 2012 unrest between the minority group and Buddhists.
Officials said the death toll of 46 is yet to be revised on Tuesday, but warned of further misery as the floods spread. "There will be more flood victims," said Phyu Lei Lei Tun, a director at the social welfare ministry, adding that flood warnings have now been issued in the low-lying Irrawaddy Delta region.
Myanmar's previous junta government was accused of callous indifference in its sluggish response to Cyclone Nargis in May 2008, which left nearly 140,000 people dead or missing.
The current quasi-civilian government has seemed eager to show it is mobilising, more so with elections looming in November.
But amid growing public discontent vented on social media, the government also threatened to prosecute anyone found spreading "false news relating to natural disaster with the intention of frightening people".
A message posted on Myanmar President Office's Facebook page, says those found to be infringing this law would face up to a year in jail or a fine.