The Philippine ferry with 82 passengers and crew caught fire as it approached a port south of Manila on Friday, Coast Guard officials said, and at least 73 people on board were rescued.
The Coast Guard said search and rescue efforts continue after dark for passengers and crew of the Asia Philippine ferry, an inter-island cargo and passenger ship from nearby Mindoro Island.
A 44-year-old woman who was among those rescued was taken to hospital with unspecified injuries.
A video released by the Coast Guard shows flames and black smoke rising from the ferry, which was alongside other ships off the port of Batangas.
The cause of the fire was not immediately clear.
The Coast Guard has said the ferry can carry up to 400 passengers, and there have been cases in the past of ferries carrying undocumented passengers in violation of regulations.
Accidents at sea in the Philippine archipelago are common due to frequent storms, poor ship maintenance, overcrowding and sporadic enforcement of safety regulations, especially in outlying provinces.
In December 1987, the ferry Dona Paz sank after colliding with a fuel tanker, killing over 4,300 people in the world’s largest peacetime maritime disaster.