Aerial footage shows the moment a tugboat sank when water entered its damaged hull.

The MTUG SUGBO 2 was carrying 9,000 litres of fuel when its steering room was flooded with seawater off the coast of Naga City in Cebu province, the Philippines on September 3.

The drone video shows the vessel being swallowed by the sea, with the crew watching helplessly from another tugboat that responded to the incident.

In a statement, the Philippine Coast Guard (PCG) said it deployed oil spill booms and absorbent pads to contain the resulting slick.

The PCG said: 'Based on the investigation, the distressed vessel called the PCG to report that they encountered hull damage on the steering portion inside the engine room.

'According to the master, he noticed the steering room was flooded due to an approximately four-inch diameter hole at the vessel's starboard quarter.

'He instructed his crew to provide a submersible pump to remove the seawater inside the steering room, but the tugboat lost its power.

'He contacted its sister ship, MTUG SUGBO 5, to connect its power source to the submersible pump, but he terminated the pumping operation due to the increase in the volume of water in the steering room.'

With the water rising rapidly, the captain ordered the crew to abandon ship.

The PCG said all seven onboard the SUGBO 2 were safe.

Investigations were ongoing to determine if the tugboat's owners were liable for any possible damages.

Officials have not yet clarified the impact of the spillage.

In February, the MT Princess Empress loaded with 900,000 litres of industrial fuel sank in Oriental Mindoro province in the Philippines and caused a disastrous oil spill that covered a 75-mile area in toxic sludge.