The fire raced through the Superferry 14 on Friday shortly after it left Manila for central and southern islands, killing one person and injuring 12 others. Witnesses reported a powerful explosion that sparked an inferno.
Most of the 744 passengers and the entire crew of 155 jumped into the sea or boarded rescue boats. About 100 passengers, however, remain missing.
Officials said the missing might have been trapped inside the blazing ferry, or drowned in Manila Bay, and some could have been picked up by fishing boats. The still-smoldering ferry was towed to shallow water but was too dangerous to search.
There had been fears that the explosion aboard the ship may have been an act of terrorism, but coast guard Vice Adm. Arturo Gosingan said the ferry was thoroughly checked by a team with bomb-sniffing dogs before it left Manila at 11 p.m. Thursday.
The fears were heightened by the sentencing in a Manila court on Friday of two Muslim extremists to life in prison for kidnapping an American in 2000.
Gina Virtusio, spokeswoman for the ship's owner, WG&A, said the fire started in the tourist section on the third deck, which includes air-conditioned sleeping cabins and a dining area.
She said the crew did a fast check of the ship to ensure no passengers were left behind before the evacuation. However, she couldn't rule out the possibility that some people might have stayed on the ship.
Relatives of the missing, many of them sleepless from waiting for news of their loves ones, gathered at Manila's coast guard headquarters.
G&A said the fire broke out near Corregidor Island, about 45 miles southwest of Manila. In addition to the 702 paying passengers and a crew of 155, there were 42 passengers or children who didn't pay for the trip.
Coast guard Apprentice Jess Galicah said the ship had a capacity of 1,672 passengers. It was built in Japan about 15 years ago and had been operated by WG&A for the last three years.
The Philippines was the site of the world's worst peacetime maritime disaster when a ferry sank after colliding with a fuel tanker in 1987, killing 4,340 people.
