Hundreds of rotting fish covered a bay sparking health concerns among locals in the Philippines.

Aerial footage shows the massive fish kill blanketing Canacao Bay off the coast of Cavite City on November 13.

The area is home to some 700 families, who said they began smelling a foul odour on Sunday, November 12. They said they were shocked to find waves of decomposing tilapia washed under stilt homes along the shore the following day.

Authorities launched a clean-up operation and collected around 220 sacks of fish for disposal.

However, residents said they were still worried as many dead fish still remained in the water.

Some 31 families living at the bay have been evacuated over health risks and the 'insufferable' smell.

The Bureau of Fisheries and Aquatic Resources (BFAR) said the cause of the fish kill has not yet been identified, adding the agency has collected fish and water samples for lab tests.

BFAR spokesman Nazer Briguera said: 'Usually, when there is a fish kill, the underlying cause is a drop in levels of dissolved oxygen in the water. Our personnel also noted possible high amounts of toxic ammonia because the fish that floated were already in the decomposing stage.'

The Cavite city government has handed out aid to affected residents, most of whom were fishermen or oyster farmers whose livelihoods were affected.