Corpses hung from trees, were scattered on sidewalks or buried in flattened buildings — some of the 10,000 people believed killed in one Philippine city alone by ferocious Typhoon Haiyan that washed away homes and buildings with powerful winds and giant waves.

As the scale of devastation became clear Sunday from one of the worst storms ever recorded, officials projected the death toll could climb even higher when emergency crews reach parts of the archipelago cut off by flooding and landslides. Looters raided grocery stores and gas stations in search of food, fuel and water as the government began relief efforts and international aid operations got underway.

Even in a nation regularly beset by earthquakes, volcanoes and tropical storms, Typhoon Haiyan appears to be the deadliest natural disaster on record.

Its sustained winds weakened to 133 km/h as it crossed the South China Sea before approaching northern Vietnam, where the typhoon made landfall early Monday after crossing the South China Sea, with winds weakened to 120 km/h, according to the Hong Kong meteorological observatory. Authorities there evacuated hundreds of thousands of people.

Among the missing are four Canadians from Montreal who were in the country to help build a church. The Filipino-Canadians had been fundraising for the church and were in a town called Bungtod — located in one of hardest hit areas of the country.

A family member confirmed to CBC News that Cristita Magno Allana, 63, her husband Amancio Allana, 63, Cristita's sister Virginia Magno Garcia, 66, and her husband Valdomar Garcia, 75, had not been heard from since Thursday.

Government officials and aid organizations are having to devise ways to deliver food, water and other supplies to hard-to-reach areas, freelance reporter Dean Bernardo told CBC News on Sunday.

Houses in Tacloban, the worst-hit city along the country's remote eastern seaboard, were destroyed by Typhoon Haiyan. (Aaron Favila/Associated Press)

"They’re finding ways and sending in generators and sending in purifiers,” he said. “And all government and private groups have been assisting in trying to send all of the goods.”

Bernardo added that "a lot of people there are going hungry and are close to desperation."

He said that only 10 per cent of the 200 members of the police force in northern Cebu have reported for work. Police reinforcements are being flown in from other regions to secure the area. There have been reports of looting.

Minister of International Development Christian Paradis said in a teleconference on Sunday that the Canadian government will match each dollar donated by Canadians to registered Canadian charities for the Philippines Crisis Matching Fund.

What's happening there is obviously devastating and far outstrips their capacity to be able to find help and support for these victims. - Foreign Affairs Minister John Baird

Paradis said that Canada would "also be deploying the Interdepartmental Strategy Support Team (ISST) to access needs and identify potential support options which could include the Disaster Assistance Response Team."

The ISST is deployed to assess the needs on the ground before a decision is made on sending the Disaster Assistance Response Team (DART) — an arm of the Canadian Forces that provides humanitarian aid.

Foreign Affairs Minister John Baird said the government is moving at "lightning speed" to make those determinations.

"What's happening there is obviously devastating and far outstrips their capacity to be able to find help and support for these victims," Baird said.

Yesterday the government announced $5 million in aid for the relief effort.

Aaron Aspi of World Vision, who is on the ground in the region, told CBC News that a northern part of Cebu is "so ravaged [it's been] literally obliterated from the map."

Haiyan hit the eastern seaboard of the Philippines on Friday and quickly barrelled across its central islands, packing winds of 235 kph that gusted to 275 kph, and a storm surge of 6 metres.

On the way to the airport we saw many bodies along the street. They were covered with just anything — tarpaulin, roofing sheets, cardboard. - Mila Ward

Hardest hit in the Philippines was Leyte Island, where officials said there may be 10,000 dead in the provincial capital of Tacloban alone. Reports also trickled in from elsewhere on the island, as well as from neighbouring islands, indicating hundreds more deaths, although it will be days before the full extent of the storm can be assessed.

"On the way to the airport we saw many bodies along the street," said Philippine-born Australian Mila Ward, 53, who was waiting at the Tacloban airport to catch a military flight back to Manila, about 580 kilometres to the northwest. "They were covered with just anything — tarpaulin, roofing sheets, cardboard." She said she passed "well over 100" bodies.

In one part of Tacloban, a ship had been pushed ashore and sat amid damaged homes.

Haiyan inflicted serious damage to at least six of the archipelago's more than 7,000 islands, with Leyte, neighbouring Samar Island, and the northern part of Cebu appearing to bear the brunt of the storm. About 4 million people were affected by the storm, the national disaster agency said.

On Leyte, regional Police Chief Elmer Soria said the provincial governor had told him there were about 10,000 deaths there, primarily from drowning and collapsed buildings. Most were in Tacloban, a city of about 200,000 that is the biggest on the island.

On Samar, Leo Dacaynos of the provincial disaster office said 300 people were confirmed dead in one town and another 2,000 were missing, with some towns yet to be reached by rescuers. He pleaded for food and water, adding that power was out and there was no cellphone signal, making communication possible only by radio.

Trail of devastation

Reports from other affected islands indicated dozens, perhaps hundreds more deaths.

Typhoon Haiyan forced millions of people to flee to safer ground, cutting power lines and blowing apart houses. (Romeo Ranoco/Reuters)

Video from Eastern Samar province's Guiuan township — the first area where the typhoon made landfall — showed a trail of devastation. Many houses were flattened and roads were strewn with debris and uprooted trees. The ABS-CBN video showed several bodies on the street, covered with blankets.

"Even me, I have no house, I have no clothes. I don't know how I will restart my life, I am so confused," an unidentified woman said, crying. "I don't know what happened to us. We are appealing for help. Whoever has a good heart, I appeal to you — please help Guiuan."

The Philippine National Red Cross said its efforts were hampered by looters, including some who attacked trucks of food and other relief supplies it was shipping to Tacloban from the southern port of Davao.

Tacloban's two largest malls and grocery stores were looted, and police guarded a fuel depot. About 200 police officers were sent into Tacloban to restore law and order.

With other rampant looting reported, President Benigno Aquino III said he was considering declaring a state of emergency or martial law in Tacloban. A state of emergency usually includes curfews, price and food supply controls, military or police checkpoints and increased security patrols.

The massive casualties occurred even though the government had evacuated nearly 800,000 people ahead of the typhoon.

Aquino flew around Leyte by helicopter on Sunday and landed in Tacloban. He said the government's priority was to restore power and communications in isolated areas and deliver relief and medical assistance.

U.S. deploys ships, aircraft

Challenged to respond to a disaster of such magnitude, the Philippine government also accepted help from abroad.

U.S. Defence Secretary Chuck Hagel directed the Pacific Command to deploy ships and aircraft to support search-and-rescue operations and fly in emergency supplies.

The United Nations said relief operations have begun but that access remained a challenge because some areas are still cut off.

Tacloban's airport suffered severe damage. (Bullit Marquez/The Associated Press)

The Philippines is annually buffeted by tropical storms and typhoons, which are called hurricanes and cyclones elsewhere. The nation is in the northwestern Pacific, right in the path of the world's No. 1 typhoon generator, according to meteorologists. The archipelago's exposed eastern seaboard often bears the brunt.

Even by the standards of the Philippines, however, Haiyan is a catastrophe of epic proportions and has shocked the impoverished and densely populated nation of 96 million people. Its winds were among the strongest ever recorded, and it appears to have killed many more people than the previous deadliest Philippine storm, Thelma, in which about 5,100 people died in the central Philippines in 1991.

'Speechless'

Defence Secretary Voltaire Gazmin said Aquino was "speechless" when he told him of the devastation in Tacloban.

"I told him all systems are down," Gazmin said. "There is no power, no water, nothing. People are desperate. They're looting."

Residents carry the body of a loved one after super Typhoon Haiyan battered the coastal Philippines city of Tacloban. (Romeo Ranoco/Reuters)

One Tacloban resident said he and others took refuge inside a Jeep, but the vehicle was picked up by a surging wall of water.

"The water was as high as a coconut tree," said 44-year-old Sandy Torotoro, a bicycle taxi driver who lives near the airport with his wife and 8-year-old daughter. "I got out of the Jeep and I was swept away by the rampaging water with logs, trees and our house, which was ripped off from its mooring.

"When we were being swept by the water, many people were floating and raising their hands and yelling for help. But what can we do? We also needed to be helped," Torotoro said.

In Torotoro's village, bodies were strewn along the muddy main road as now-homeless residents huddled with the few possessions they managed to save. The road was lined with toppled trees.

UNICEF estimated that 1.7 million children live in areas affected by the typhoon, according to the agency's representative in the Philippines, Tomoo Hozumi. UNICEF's supply division in Copenhagen was loading 60 metric tons of relief supplies for an emergency airlift expected to arrive in the Philippines on Tuesday.

"The devastation is ... I don't have the words for it," Interior Secretary Mar Roxas said. "It's really horrific. It's a great human tragedy."

In Vietnam, about 800,000 people having been evacuated from the central-north coastal regions.

Four people in three central Vietnamese provinces died while trying to reinforce their homes for the storm, the national floods and storms control department said Sunday.