(CNN) -- Super Typhoon Haiyan -- perhaps the strongest storm ever -- plowed across the central Philippines on Friday, leaving widespread devastation.
It roared onto the country's eastern island of Samar at 4:30 a.m., flooding streets and knocking out power and communications in many areas of the region of Eastern Visayas, and then continued its march, barreling into five other Philippine islands as it moved across the archipelago.
At least three people were killed and seven hurt, the National Disaster Risk Reduction and Management Council said Friday.
The state-run Philippines News Agency, citing unconfirmed TV reports, said "around 20" people drowned after a storm surge struck Friday morning in Palo, a town on the island of Leyte, which abuts Samar.
"Most of the fatalities sustained massive injuries in the head and upper part of the body, indicative that strong waves dashed them against hard objects," it reported, adding that nine of the dead were minors.
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Experts predicted the casualty toll would soar once aid workers get to the hardest-hit areas.
About 125,000 people took refuge in evacuation centers, and hundreds of flights were canceled.
With sustained winds of 315 kph (195 mph) and gusts as strong as 380 kph (235 mph), Haiyan may be the strongest tropical cyclone to hit land anywhere in recorded history. It will take further analysis after the storm passes to establish whether it is a record.
Its speed -- westward at 41 kph (25 mph) -- meant the worst was over quickly. But the damage was still severe. "About 90% of the infrastructure and establishments were heavily damaged," Gwendolyn Pang, the secretary general of the Philippine National Red Cross, told CNNI.
About 25 areas were hit, she said, adding that assessment teams were prepared to enter the stricken areas as soon as conditions allowed.
But they cannot do it alone, she said: "We will be definitely needing more support for this one."
She said floodwater was as high as 10 feet in some areas.
Maryann Zamora, a field communications specialist for the charity World Vision, said her organization "has been working through so many disasters, so many typhoons -- but this is quite different."
"This is the strongest I ever felt so far," she said by phone from the island of Cebu.
Category 5 strength
Haiyan, known in the Philippines as Yolanda, retained much of its force as it moved westward with sustained winds of 295 kph (183 mph), which puts it well above the 252 kph (157 mph) threshold for a Category 5 hurricane, the highest category on the Saffir--Simpson hurricane wind scale.
Video showed streets flooded with debris and sheets of metal flying through the air.
Gov. Roger Mercado of Southern Leyte, a province in Eastern Visayas near the storm's path, said Friday morning that fallen trees had made all roads impassable. "We don't know the extent of the damage," he said. "We are trying to estimate this. We are prepared, but this is really a wallop."
With sea travel suspended in many areas, more than 3,000 travelers were stranded in ports, the council said.
The typhoon was moving away from the Philippines early Saturday into the South China Sea toward Vietnam.
Meteorologists said it was maintaining super typhoon intensity throughout its passage over the Philippines. A super typhoon has surface winds that sustain speeds of more than 240 kph (149 mph) for at least a minute, according to the U.S. National Oceanic and Atmospheric Administration.
Haiyan was so large in diameter that, at one point, its clouds were affecting two-thirds of the country, which stretches more than 1,850 kilometers (1,150 miles). Tropical storm-force winds extended 240 kilometers from the typhoon's center.
'Very real danger'
Ahead of the typhoon's arrival, thousands of people were moved from particularly vulnerable areas in the city of Tacloban, which is in a coastal area of the region that bore the initial brunt of the storm.
Communications with Tacloban, which has a population of around 200,000, were disrupted after the typhoon struck. Video aired by CNN affiliate ABS-CBN showed streets in the city filled with water and debris.
In a speech Thursday, President Benigno S. Aquino III warned residents of the "calamity our countrymen will face in these coming days."
"This is a very real danger, and we can mitigate and lessen its effects if we use the information available to prepare," he said.
Authorities had aircraft ready to respond, and officials had placed relief supplies in the areas that were expected to get hit, Aquino said.
"The effects of this storm can be eased through solidarity," he said.
Earthquake survivors vulnerable
Authorities warned people in provinces across the country to prepare for possible flash floods, landslides and a storm surge as high as 7 meters (23 feet). About 125,000 people nationwide were moved to evacuation centers.
Among the most vulnerable were people living in tents on the central Philippine
island of Bohol, where a 7.1-magnitude earthquake hit last month, killing at least 222 people, injuring nearly 1,000 and displacing about 350,000, according to authorities.
On Friday, they got a second jolt -- this time from the typhoon's winds and rain, but they were spared a direct hit.
"For the past three weeks, people are still experiencing aftershocks," said Aaron Aspi, a communications specialist in Bohol for World Vision. "And at the same time, these rains are giving them a really hard time."
Aspi said that despite living in drenched tents, many people were afraid to move to sturdier structures because of the aftershocks.
Beach resort threatened
Another island near the storm's path was the popular beach resort of Boracay. Some tourists there cut short vacations Thursday to get away from the possible danger.
In near an area of the Pacific Ocean where tropical cyclones form, the Philippines regularly suffers severe storm damage.
An average of 20 typhoons hit the nation every year.
In December, Typhoon Bopha wreaked devastation on the southern Philippine island of Mindanao. The storm, the most powerful to hit the country last year, is estimated to have killed as many as 1,900 people.
According to the Civil Aviation Authority of the Philippines (CAAP), operations were shut at airports in areas placed under storm warning signal No. 4.
As of Friday afternoon, airports were closed in Busuanga, Bacolod, Tacloban, Surigao, Kalibo, Roxas, Caticlan, Iloilo, Romblon, Legazpi, Masbate and Dumaguete.
For the latest aviation updates, travelers can follow @CAAP_Operations on Twitter.
Airlines affected by the typhoon include:
Philippines Airlines (PAL)
In a statement from PAL, the airline said all flights to and from the following destinations were canceled Friday: Tacloban, Calbayog, Catarman, Cebu, Tagbilaran, Dumaguete, Bacolod, Iloilo, Roxas, Kalibo, Caticlan, Masbate, Legaspi, Naga, Puerto Princesa, Busuanga, Butuan, Surigao, Cagayan de Oro, Ozamiz, Dipolog, Davao, General Santos, Zamboanga, Sanga- Sanga and Jolo.
The following international flights were also canceled: PR434/433 Cebu-Narita-Cebu; 875/876 Manila-Kuala Lumpur-Manila; 800 Manila-Singapore; 801 Singapore-Manila (November 9).
All PAL international flights except PR434/433 Cebu-Narita-Cebu and PR 2918/2919 Manila-Laoag-Manila were running as scheduled.
"PAL/PALex passengers with flights to typhoon-affected areas may rebook their flights within the next 30 days from the original flight date, with rebooking fees and fare difference waived," says the statement.
For more information on flights, visit www.philippineairlines.com.
As of Friday morning, Cebu Pacific canceled approximately 125 round-trip domestic flights and four round-trip international flights from November 8 to 10.
"Travelers affected by these cancellations may rebook their flights for travel within 30 days, free of charge," said the statement issued by the airline. "They may also reroute to the nearest alternate airport, or opt for full refund or full travel fund."
This includes flights to or from Cebu, Tacloban, Tagbilaran, Iloilo, Bacolod, Kalibo, Caticlan (Boracay), Roxas, Dumaguete, Legazpi, Naga, Virac, Puerto Princesa, Busuanga (Coron), San Jose, Siargao, Surigao, Pagadian, Butuan, Ozamiz, Cagayan de Oro and Dipolog.
Tiger Air canceled all domestic flights on Friday, as well as its international flight from Kalibo to Singapore.
Flights via Clark International Airport to Singapore, Hong Kong and Bangkok were operating.
"Passengers are advised to rebook without penalties for travel within 30 days from original flight," said the statement. "They are also requested to call TigerAir Philippines hotline at 798-44-88 for further details."
The following Philippines' AirAsia and AirAsia Zest flights were canceled on Friday, November 8.
• Manila-Cebu-Manila route with flight nos. PQ 7489/7488.
• Manila-Kalibo-Manila flight nos. Z2 272/273 and Z2 713/714.
• Manila-Tagbilaran-Manila route with flight nos. Z2 354/355, Z2 352/353, and z2 350/351.
• Manila-Iloilo-Manila route with flight nos. Z2 310/311.
• Manila-Cebu-Manila route flight nos. Z2 384/385 and Z2 771/772.
• Manila-Bacolod-Manila route flight nos. Z2 330/331.
• Manila-Cagayan de Oro-Manila route with flight nos. Z2 348/349 and Z2 340/341.
Those affected will be offered a free flight within 14 days on the same route, subject to availability; full credit, valid for 90 days; or a refund, said a post on its Facebook page.
The AirAsia hotline in the Philippines is 02-742-2742, Mondays-Sundays, 7 a.m.-11p.m. Travelers can also inquire about their flights by messaging the AirAsia Twitter feed, @askairasia.
CNN's Aliza Kassim, Karen Smith, Elwyn Lopez, Judy Kwon, Taylor Ward, Brandon Miller, Ivan Cabrera and Mari Ramos contributed to this report.
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