Thousands have been left homeless after coastal villages on Leyte were wiped out in an instant.
Philippine President Benigno Aquino has promised that help is on the way for the hundreds of thousands hit by Typhoon Haiyan, as the death toll was expected to reach 10,000 in one province alone.
Thousands of survivors need access to fresh food and water after the storm flattened buildings and cut off communications on Friday.
“We are addressing first the needs of those who are still living, especially those that are injured, the need for food and need for water,” the president said as he visited the worst-hit city, Tacloban, in Leyte province on Sunday.
Aquino added that security would be put in place in the area.
“We have around 300 policemen and soldiers who can rotate and restore peace here. Later tonight, there will be several armoured vehicles from our army arriving to show the strength of the state and stop those who started the looting here,” he said.
Aquino’s pledge came as the regional police chief for eastern Leyte province said 10,000 people were believed to have died on that island alone, mostly by drowning and from collapsed buildings.
“We had a meeting last night with the governor and, based on the government’s estimates, initially there are 10,000 casualties [dead],” Chief Superintendent Elmer Soria said in the provincial capital, Tacloban.
Soria said that as much as 80 percent of the area in the path of Haiyan in Leyte province was destroyed.
Al Jazeera’s Wayne Hay, reporting from Tacloban, said the city was in disarray.
“People are still searching for missing friends and family members, and for any food and water they can get their hands on,” he said.
He reported that the military was arriving at the destroyed Tacloban airport and bringing some supplies, but that it was “clearly still not enough”.
“One of the biggest problems is shelter, and those military planes have been taking a very small number of people away to other parts of the country,” he said.
Meanwhile, a huge international relief effort was being put together for the victims.
The US defence secretary, Chuck Hagel, said he had directed the US Pacific Command to deploy ships and aircraft to support search-and-rescue operations and airlift emergency supplies.
The president of the European Commission, Jose Manuel Barroso, said that the EC was ready to contribute with “urgent relief and assistance in this hour of need”.
The Philippines has yet to fully resume communications with officials in Tacloban, a city of about 220,000 that suffered the worst of the typhoon. Reports say the sea flooded the entire city.
It was a similar situation in the town of Palo, further south. It was said to be under three and a half metres of water.
“Imagine a strip 1km deep inland from the shore, and all the shanties, everything, destroyed,” the interior secretary, Mar Roxas, said after visiting coastal towns in Leyte.
One UN official said the damage was similar to the devastation caused by the Indian Ocean tsunami in 2004.
After hitting the Philippines, the weakening storm headed towards Vietnam.
More than 883,000 people have been evacuated from their homes in central and northern Vietnam as forecasters predict the typhoon would make landfall there on Monday morning.
Six people were reported killed and dozens wounded during heavy winds and storms in central provinces as Haiyan approached the coast.