Manila - Rescuers raced against time Wednesday to search for nine people missing after the sinking of a motorized wooden boat in the eastern Philippines that killed 42 people, officials said.

Raffy Alejandro, regional chief of the Office of Civil Defence, said 11 of the 42 confirmed fatalities were children and included infants.

He said 100 people survived the sinking of the boat Tuesday off Dimasalang town in Masbate province, 420 kilometres south-east of Manila.

Alejandro said authorities discovered that the ill-fated boat was carrying a total of 151 people, more than the 119 reported in its manifest.

"The rescue operation is ongoing," he said. "An air force helicopter is helping in the rescue."

The boat was about five kilometres from shore when it was struck by a sudden gust of wind, causing it to capsize.

Deputy presidential spokesman Lorelei Fajardo said the government was "deeply saddened" by the accident.

She said the administration was coordinating with local authorities "to extend all necessary help and support to rescue the remaining missing passengers."

In June, a passenger ferry carrying more than 800 people sank in storm-whipped seas off the nearby island of Romblon. Only 56 people survived in one of the worst maritime accidents in the Philippines.

Sea travel is a major mode of transportation in the Philippines, an archipelago of more than 7,000 islands.

The country was the site of the world's worst peacetime shipping disaster in 1987 when more than 4,000 people perished in a collision between a ferry and an oil tanker just before Christmas. (dpa)