TACLOBAN, Philippines — As many as 10,000 people are believed to have died in one Philippine city alone when one of the worst storms on record sent giant sea waves, washing away homes, schools and airport buildings, officials said Sunday. Ferocious winds ravaged several central islands, burying people under tons of debris and leaving corpses hanging from trees.

Regional police chief Elmer Soria said he was briefed by Leyte provincial Gov. Dominic Petilla late Saturday and told there were about 10,000 deaths in the province, mostly by drowning and from collapsed buildings. The governor’s figure was based on reports from village officials in areas where Typhoon Haiyan slammed Friday.

Tacloban city administrator Tecson Lim said that the death toll in the city alone “could go up to 10,000.” Tacloban is the Leyte provincial capital of 200,000 people and the biggest city on Leyte Island.

On Samar Island, which is facing Tacloban, Leo Dacaynos of the provincial disaster office said Sunday that 300 people were confirmed dead in Basey town and another 2,000 are missing.

He said that the storm surge caused sea waters to rise 6 meters (20 feet) when Typhoon Haiyan hit Friday, before crossing to Tacloban.

There are still other towns on Samar that have not been reached, he said, and appealed for food and water. Power was knocked out and there was no cellphone signal, making communication possible only by radio.

Reports from the other four islands were still coming in, so far with dozens of fatalities.

The typhoon barreled through six central Philippine islands on Friday, wiping away buildings and leveling seaside homes with ferocious winds of 235 kilometers per hour (147 miles per hour) and gusts of 275 kph (170 mph). By those measurements, Haiyan would be comparable to a strong Category 4 hurricane in the U.S., and nearly in the top category, a 5.

It weakened Sunday to 166 kph (103 mph) with stronger gusts and was forecast to loose strength further when it hits northern Vietnam’s Thanh Hoa province early Monday morning.

In hardest-hit Tacloban, about 300-400 bodies have already been recovered but there are “still a lot under the debris,” Lim said. A mass burial was planned Sunday in Palo town near Tacloban.

Many corpses hung on tree branches, buildings and sidewalks.

“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.

“They were covered with just anything — tarpaulin, roofing sheets, cardboards,” she said. Asked how many, she said, “Well over 100 where we passed.”

Interior Secretary Mar Roxas said a massive rescue operation was underway. “We expect a very high number of fatalities as well as injured,” Roxas said after visiting Tacloban on Saturday. “All systems, all vestiges of modern living — communications, power, water — all are down. Media is down, so there is no way to communicate with the people in a mass sort of way.”

President Benigno Aquino III, who landed in Tacloban on Sunday to get a firsthand look at the disaster, said the casualties “will be substantially more” than the official count of 151 — but gave no figure or estimate. He said the government’s priority was to restore power and communications in isolated areas to allow for the delivery of relief and medical assistance to victims.