A file photo of killer whales hunting a seal.

• A new BBC documentary shows a pod of killer whales hunting a seal using a sophisticated technique. 
• They used "wave crashing," creating a wave to break up an ice platform and trap the seal on it.
• The technique is used by only about 100 killer whales around the world.

Dramatic footage showed killer whales using a rare hunting technique to trap and kill a seal in the icy waters surrounding Antarctica.

The video, part of the BBC's new "Frozen Planet II" documentary released Sunday in the UK, shows four killer whales that attacked a Weddell Seal. The seal had found refuge on a platform made of ice floating on water.

The killer whales started by swimming side by side, which created a wave that cracked the seal's large ice platform into a smaller one, making it vulnerable.

A second wave the whales generated knocked the seal off the ice into the water, where the whales could attack it. 

Once the seal was in the water, the whales used another hunting technique: blowing bubbles to confuse the seal, which made it easier to catch. 

A Weddell Seal floats among pieces of ice in Antarctica on February 20, 2019.

There are only about 100 killer whales on Earth that use this sophisticated coordinated hunting technique, per the documentary, narrated by the naturalist Sir David Attenborough. It is known as "wave-crashing." 

Killer whales are known for their precise targeted attacks. A recent report showed the animals are able to rip out great white sharks' internal organs, such as their liver, with surgical precision.

An expert previously told Insider they might do so by using their echolocation to find the fattiest organs in their prey. 

Killer whales aren't put off by hunting animals larger than them. Rare footage released earlier this year showed them attacking and killing at least two blue whales, the largest animals on the planet. 

The orcas were recorded swimming into the mouth of the blue whales to chomp off their rich tongues.