Survivors walk on a road amidst heavy downpour after Typhoon Haiyan battered Tacloban city in central Philippines November 10, 2013. [Photo/Agencies]

TACLOBAN, Philippines - One of the most powerful storms ever recorded killed at least 10,000 people in the central Philippines province of Leyte, a senior police official said on Sunday, with coastal towns and the regional capital devastated by huge waves.

Super typhoon Haiyan destroyed about 70 to 80 percent of the area in its path as it tore through the province on Friday, said chief superintendent Elmer Soria, a regional police director.

Most of the deaths appear to have been caused by surging sea water strewn with debris that many described as similar to a tsunami, which levelled houses and drowned hundreds of people.

The national government and disaster agency have not confirmed the latest estimate of deaths, a sharp increase from initial estimates on Saturday of at least 1,000 killed.

"We had a meeting last night with the governor and the other officials. The governor said, based on their estimate, 10,000 died," Soria said. "The devastation is so big."

Haiyan, a category 5 typhoon that churned through the Philippine archipelago in a straight line from east to west, packing wind gusts of around 275 kph (170 mph), weakened significantly before hitting northern Vietnam on Sunday.

Leyte province's capital of Tacloban, with a population of 220,000, bore the brunt of Haiyan, which was possibly the strongest storm ever to make landfall.

The city and nearby villages as far as one kilometre from shore were flooded by the storm surge, leaving floating bodies and roads choked with debris from fallen trees, tangled power lines and flattened homes. TV footage showed children clinging to rooftops for their lives.

"From a helicopter, you can see the extent of devastation. From the shore and moving a kilometre inland, there are no structures standing. It was like a tsunami," said Interior Secretary Manuel Roxas, who had been in Tacloban since before the typhoon struck the city, about 580 km (360 miles) southeast of Manila.

"I don't know how to describe what I saw. It's horrific."

City officials said they were struggling to retrieve bodies and send relief supplies to survivors. They also reported widespread looting as authorities struggled to restore order and repair shattered communications.

"There is looting in the malls and large supermarkets. They are taking everything even appliances like TV sets, these will be traded later on for food," said Tecson John Lim, the Tacloban city administrator.

"We don't have enough manpower. We have 2,000 employees but only about 100 are reporting for work. Everyone is attending to their families."

Lim said city officials had so far only collected 300-400 bodies, but believed the death toll in the city alone could be 10,000.

"The dead are on the streets, they are in their houses, they are under the debris, they are everywhere," he said.

International aid agencies said relief efforts in the Philippines are stretched thin after a 7.2 magnitude quake in central Bohol province last month and displacement caused by a conflict with Muslim rebels in southern Zamboanga province.

The World Food Programme said it was airlifting 40 tonnes of high energy biscuits, enough to feed 120,000 people for a day, as well as emergency supplies and telecommunications equipment.

Tacloban city airport was all but destroyed as seawaters swept through the city, shattering the glass of the airport tower, levelling the terminal and overturning nearby vehicles.

Airport manager Efren Nagrama, 47, said water levels rose up to four metres (13 feet).

"It was like a tsunami. We escaped through the windows and I held on to a pole for about an hour as rain, seawater and wind swept through the airport," he said. "Some of my staff survived by clinging to trees. I prayed hard all throughout until the water subsided."