Authorities warned backpackers and residents to be careful as crocodiles were spotted swimming off a tourist beach in the Philippines.

Drone footage shows the large saltwater reptile splashing around in the turquoise waters of Sarangani Bay in Sarangani province on September 11. It was estimated to be 13 feet and was believed to be basking in the sun to regulate its body temperature.

Shalimar Disomangcop, Sarangani provincial environment and natural resources officer (PENRO), said the croc was reported by a villager monitoring the beach.

He said: 'This could be the same crocodile sighted recently in Minanga, Buayan, General Santos City as the sightings occurred just days apart. Identifying the crocodile's presence is important, given their highly territorial nature and potential threat to human safety.'

On September 1, another crocodile sparked panic when it surfaced near a fishing boat sailing off Minanga town.

Cirilo A. Lagnason, Jr., Sarangani Bay Protected Seascape protected area superintendent, said: 'We advise the public to stay vigilant and avoid encounters with the crocodile, particularly residents near the mangrove areas of Minanga, Buayan, General Santos City, and Lun Padidu, Malapatan, Sarangani Province.'

The Department of Environment and Natural Resources (DENR) Region 12 said saltwater crocodiles usually breed during the rainy season in September and October, during which the beasts become especially aggressive.

In July, lifeguards caught a huge crocodile swimming on the shore of a tourist beach in Aklan province.

Residents on the tropical island of Boracay initially thought the reptile was a piece of driftwood - only to realise it was actually a deadly croc.

Authorities caught the animal in a net and took it to the local wildlife office facility to be relocated. It was believed to have been swept away by strong currents away from its natural habitat and into the beach.