A massive oil spill in the Philippines' capital Manila has shuts down parts of the capital's waterways vital to the nation's fishing industry and affected the livelihood of at least 40,000 people living along a Manila bay now coated about 132,000 gallons of diesel fuel.

The Associated Press reported dead fishe floating on the water and residents sick from fumes as authorities said an the spill was hitting 12.4 miles of coastline. Worse, officials are unsure of the leak, saying that it is either from an oil terminal on the bay or a ship that was unloading diesel.

"I cannot say that we have contained it because it has affected so wide an area," Joel Garcia, chief commodore of the coastguard said to reporters.

In total the spillage stretched 9.3 miles from the shore into the sea covering around 120 square miles.

Jose Ricafrente, mayor of Rosario fishing town, told AFP that 40,000 people depend on fishing and shellfish industries in the bay.

"Fish and shellfish are floating up dead. It could be months before the shellfish industry is revived unless the water is cleaned up soon," Ricafrente said. Adding that these 40,000 are temporarily without jobs.

Depending on the sea currents and weather the oil will remain in the bay for the next few days or up to a week, Garcia said.