Manila  - The death toll from Typhoon Fengshen in the Philippines has risen to 622 with nearly 1,000 people still missing, mostly from the sinking of a passenger ferry, officials said Thursday.

The Coast Guard said 124 people who were on board the MV Princess of the Stars have been confirmed killed after it capsized Saturday in turbulent seas off Sibuyan Island, 300 kilometres south of Manila.

More than 680 passengers and crew members were still missing and feared dead in one of the country's worst maritime disasters.

At least 498 people were killed in other accidents caused by Fengshen with 263 still missing, the Office of Civil Defence said.

Most fatalities drowned in flooding that authorities described as the worst in decades in some affected provinces, including Iloilo.

The Coast Guard said 56 people survived the sinking of the Princess of the Stars. It said eight additional survivors found earlier in two villages on Sibuyan Island were confirmed to have been aboard the ill-fated ferry when it capsized.

More bodies have been spotted in waters and shores as far as 100 kilometres away from the site of the accident.

Some coastal communities have buried the decomposing bodies in mass graves because of a lack of equipment and chemicals to preserve them.

Coast Guard and Navy teams were continuing to scour nearby waters and shores for the missing as authorities study a plan to cut into the submerged vessel to speed up the retrieval of bodies.

Transportation Undersecretary Elena Bautista said experts were plotting out areas that must be avoided to prevent an oil spill.

"We know where the fuel is, so we know which are not to touch," she told a Manila radio station. "We also have to avoid the cargo compartment."

Bautista said divers have been instructed to open all doors and windows of the ship to allow faster recovery of bodies trapped inside the vessel.

Maritime authorities have began an investigation into the accident while all 14 remaining vessels of the Sulpicio Lines, which owns the capsized ferry, have been grounded.

The Princess of the Stars was the fourth Sulpicio Lines ship to sink since 1987 when its passenger ferry Dona Paz collided with an oil tanker just before Christmas, killing 4,341 people in the world's worst peacetime shipping disaster.

In October 1988, another Sulpicio Lines ferry sank during a typhoon, killing 250 people. In 1998, another of the company's ships sank, leaving 70 dead and 80 missing. (dpa)