The ship left central Cebu City for Iloilo City late Wednesday and sank near Bantayan island off the northern tip of central Cebu island, about 300 miles southeast of Manila.
A Philippines Air Force captain says a passing ship rescued about 180 people, but so far there's no word on the fate of the others. Officials say there were 630 people aboard -- 578 passengers and 52 crew members.
Defense Secretary Orlando Mercado says several Philippine Navy ships are helping in the search and rescue. Although there's no word on what caused the sinking, reports indicate there were strong winds and fog in the area.