Two orcas, also known as killer whales, were spotted in the waters of Terengganu, Malaysia on July 16, 2019.

It is believed to be the first time these marine mammals have been sighted in the area.

A "historic" moment

According to Malay Mail, the orcas first caught the eye of some workers on the nearby Petronas oil drilling platform.

Rantau Abang Fisheries Research Institute (FRI) Marine Mammals branch head, Mohd Tamimi Ali Ahmad, confirmed in a statement that the creatures were orcas.

He believed that the pair spotted were a male and female.

Based on past records, Tamimi added that orcas had never before appeared in Terengganu waters, and that the July 16 event could be described as a "historic" moment.

The video of the orcas, presumably captured by one of the Petronas workers, shows the pair of black-and-white mammals swimming close to the surface, occasionally coming up to breathe.

Orcas are actually dolphins

Despite being labelled "killer whales", orcas are actually dolphins, and similarly are smart and social creatures.

Their existence was popularised by the Free Willy movies franchise.

The species is widely distributed and can be found from the polar regions to the equator.

Orcas are apex predators in the marine food chain, preying on a wide range of animals such as fish, seals, penguins, seabirds and even whales, according to National Geographic.

They can also grow to a massive lengths of up to almost 10m.

The pair spotted in Malaysia were estimated to be between six and eight metres long, weighing between 5,000kg and 6,000kg each.

Due to their instinctual drive to swim far -- they can swim up to 65km a day -- and dive hundreds of metres deep, these creatures cannot be kept in captivity.

Those that are often suffer from extreme stress and boredom.

Top photo from Bernama / FB and George Karbus Photography / IG