Killer whales collided and damaged sailboats off the Spanish and Portuguese coasts, leaving marine experts perplexed by sudden aggressive encounters.

Orcas are very intelligent and are known to follow boats closely, but it is not unusual for ships to attack again and again. The Guardian reported.

Over the past two months, the orca confrontations have destroyed several boats and left at least one sailor with bruises on collision.

In the most recent accident on Friday, a 36-foot boat was near A Coruña, on the northern coast of Spain, when the Orca rammed its stern about 15 times, the port reported.

A similar incident was reported on August 30, when a coast guard vessel called the radio to say it was “under attack” by killer whales.

On the same day, the Spanish sea yacht, the Mervac, lost part of its rudder in the face of killer whales.

Then on July 29, he surrounded nine orcas off Cape Trafalgar in southwestern Spain.

The port reported that orcas rammed the ship’s hull for more than one hour – turning the boat 180 degrees, disrupting the engine and destroying the rudder.

The port reported that scientists described their recent behavior as “extremely unusual” and “alarming.”

The outlet reported that Dr Ruth Esteban has researched orcas off Gibraltar for many years and believes that the same group of orcas are responsible for the accidents, saying it is an abnormal behavior of the species.

Meanwhile, Spanish maritime authorities have warned ships to “turn away” from any orca, the report said.