Manila  - At least nine people were killed when a passenger motorboat capsized amid bad weather in the central Philippines on Thursday, local officials said.

It was the second motorboat to sink in the Philippines in three days.

The boat was battered by strong waves spawned by a tropical depression while on its way to an island off Concepcion town in Iloilo province, 450 kilometres south-east of Manila.

Concepcion town Vice mayor John Arcosa said an undetermined number of people were missing from the accident.

He said rescue teams were having difficulty reaching the site because of huge waves.

On Tuesday, a motorized wooden boat sank off Masbate province, 420 kilometres south of Manila, killing 42 people.

According to initial investigation, the boat was overloaded and capsized when a sudden gust of wind struck it shortly after leaving the port.

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)