After Haiyan

"The last time I saw something of this scale was in the aftermath of the Indian Ocean tsunami," said Sebastian Rhodes Stampa, head of the UN Disaster Assessment Co-ordination Team sent to Tacloban in the Philippine archipelago.

The death toll from Typhoon Haiyan is expected to rise sharply this weekend as rescue workers reach areas cut off by the fast-moving storm - the circumference of which eclipsed the whole of the Philippines - which late yesterday was heading for Vietnam.

Roads in the Philippines coastal city of Tacloban in the central Leyte province, one of the worst-hit areas, were either under water or blocked by fallen trees, power lines and debris from homes that had blown away.

Bodies covered in plastic sheets were lying on the streets. In the aftermath, people were seen weeping while retrieving bodies of loved ones from inside buildings.

"This is destruction on a massive scale. There are cars thrown like tumbleweed and the streets are strewn with debris," said Rhodes Stampa.

The category five "super typhoon" weakened to a category four storm yesterday, though forecasters said that it could strengthen again over the South China Sea en route to Vietnam.

Authorities in 15 provinces in Vietnam have started to call back boats and prepare for possible landslides. Nearly 300,000 people were moved to safer areas in two provinces alone, according to the government's website.

The Philippines has yet to restore communications with officials in Tacloban, a city of about 220,000, but a Red Cross estimate said the number of dead could be upwards of 1200 people across the Philippines, 1000 of them in Tacloban city. Thousands more have been injured. The national disaster agency has yet to confirm the figures.

"An estimated more than 1000 bodies were seen floating in Tacloban as reported by our teams," Gwendolyn Pang, secretary general of the Philippines Red Cross told reporters by satellite phone. "In Samar, about 200 deaths. Validation is ongoing."

Broken power poles, trees, bent tin roofs and splintered houses littered the streets of the city, which lies about 360 miles southeast of the capital, Manila. The airport was nearly destroyed as raging 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 13ft in the airport.

He said: "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. Some of my staff survived by clinging to trees. I prayed hard all throughout until the water subsided."

Major Rey Balido, a spokesman for the national disaster agency, said that almost all houses were destroyed, many totally.

Local television network ABS-CBN showed images of looting in one of the city's biggest shopping centres, with residents carting away everything from electrical appliances to suitcases and grocery items.

Television reporter Ted Failon, who was able to report only briefly on Friday from Tacloban, said the storm surge was "like the tsunami in Japan".

"The sea engulfed Tacloban," he said, explaining that a major part of the city is surrounded on three sides by the waters between Leyte and Samar islands.

Across the country, about one million people took shelter in 37 provinces after President Benigno Aquino appealed to those in the typhoon's path to leave vulnerable areas."For casualties, we think it will be substantially more," Aquino told reporters.

Officials started evacuating low-lying areas, coastlines and hilly villages as early as three days before the typhoon struck on Friday, but not all headed the call to leave.

"I saw those big waves and immediately told my neighbours to flee," said Floremil Mazo, a villager in southeastern Davao Oriental province.

Vice-mayor Jim Pe of Coron town on Busuanga, the last island battered by the typhoon before it moved out to the South China Sea, said most of buildings there had been destroyed or damaged. Five people drowned in the storm surge and three others are missing, he said.

"It was like a 747 flying just above my roof," Pe said by phone, describing the sound of the winds. He said his family and some of his neighbours whose houses were destroyed took shelter in his basement.

Meteorologists said the impact may not be as strong as feared because the storm was moving so quickly, reducing the risk of flooding and landslides from torrential rain, normally the biggest causes of typhoon casualties in the Philippines.

Ferry services and airports in the central Philippines remained closed, hampering aid deliveries to Tacloban, although the military confirmed three C-130 transport planes managed to land at its airport yesterday.

At least two people were killed on the tourist destination island of Cebu, with six others dying in two further provinces, radio reports said.

"I never thought the winds would be that strong that they could destroy my house," LynLyn Golfan of Cebu said while sifting through the debris.

Weather officials said Typhoon Haiyan had sustained winds of 147mph with gusts of 170mph when it made landfall.

At one point the super typhoon had been stronger than it was when it hit land, with winds gusting up to 235mph, making it among the most powerful ever.

Aaron Aspi, of humanitarian agency World Vision, described the typhoon in a telephone interview with reporters. He had travelled to the island of Bohol from Manila to help people recover from an earthquake last month. The tremor killed around 200 people and left thousands homeless. He said many of the homeless people were reluctant to shelter from the typhoon inside buildings because they were so scared of the continuing aftershocks from the earthquake. But when the wind blew away their tents, they rushed to already crowded evacuation centres.

Aspi added: "We get around 25 cyclones per year but I have never seen winds like this. If I did not hang on to railings when I walked between buildings, I would have been blown away."

Hurricanes, cyclones and typhoons are the same thing, they just have different names in different parts of the world.

Haiyan was the second category five typhoon to hit the Philippines this year after Typhoon Usagi in September. An average of 20 typhoons strike every year - however, Haiyan was the 24th so far this year.

Last year, Typhoon Bopha flattened three towns in the southern Mindanao region of the Philippines, killing 1100 people and causing damage estimated at the equivalent of more than £625 million.

By yesterday afternoon, Typhoon Haiyan was hovering in southwestern Occidental Mindoro province. It was forecast to make landfall in Vietnam at around 10am local time today, somewhere between Danang and Quang Ngai, and move northwest.

Vietnamese authorities in four central provinces began evacuations, moving more than 500,000 people from high-risk areas to government buildings, schools and other concrete homes able to withstand strong winds.

"The evacuation is being conducted with urgency," disaster official Nguyen Thi Yen Linh said from central Danang City, where about 76,000 people were being moved to safety.

Hundreds of thousands of others were being taken to shelters in the provinces of Quang Ngai, Quang Nam and Thua Thien Hue. Schools were closed and two deputy prime ministers were sent to the region to direct the preparations.

Many scientists now believe that the increase in strength of storms such as Typhoon Haiyan is linked to sea temperature. As the oceans warm with climate change, there is extra energy in the system.

According to Naderev Saño, who was chief negotiator of the Filipino delegation at last year's annual United Nations climate talks in Doha, each destructive typhoon season costs the Philippines 2% of its GDP, and the reconstruction costs a further 2%.

"This means we lose nearly 5% of our economy every year to storms," Saño was quoted as saying at last years's climate talks.

"We have received no climate finance to adapt or to prepare ourselves for typhoons and other extreme weather we are now experiencing. We have not seen any money from the rich countries to help us to adapt.

"We cannot go on like this. It cannot be a way of life that we end up running always from storms."