The boat was carrying at least 27 immigrants in total, with some reports saying that as many as 32 were on board. 23 people were confirmed to have survived.

Four of the survivors were reported to have suffered hypothermia, as the Atlantic waters off Cadiz are now below 15 degrees Celsius. One of them, reported AFP, needed to the hospitalized.

The incident just off Spain's short stretch of Atlantic Coast was not typical.

According to eyewitnesses on the ground, a smuggler forced migrants to jump off the boat, while some were forcibly pushed off the vessel as it approached land. A smuggler was reportedly seen as threatening migrants with a gun if they failed to comply.

Local journalist Juan Miguel Garrido commented on X that "criminal human traffickers murder four migrants ... who gave them all their savings in search of a better life, fleeing hunger, misery..."

Inquiry to interpret tragic events

Images from the scene shared by Garrido and others on social media show a black inflatable speedboat in heavy tidal waves. People onboard are seen pushing others off the side.

The authenticity of the video footage has not been independently established yet.

Spain has meanwhile launched an inquiry into the exact circumstances surrounding the incident.

Also read: Spain spends millions to tackle Canary Islands 'migration flow'

Rescue too late for some

A group of around 20 windsurfers observed the ordeal from the shore and rushed to the rescue of the migrants stuck in the choppy waters.

"We went towards … the migrants and by that time, within one minute or two, there were already three of them facing down," Javier Gonzalez, one of the windsurfers, told a TV local station.

"What we did first was to take the ones facing down and then pulling the rest out."

However, the help came too late for four of the migrants, who were declared dead shortly thereafter.

Also read: Spain sends drones, personnel to Senegal to stop boats departing for Canary Islands

An unlikely destination

Cadiz is located on the southern tip of Spain, about 20 kilometers off the North African coast. But despite this proximity, Cadiz is not a common arrival sport for migrants departing from North Africa, as the sea conditions surrounding the city are volatile.

Furthermore, surveillance has been beefed up in that region due to its proximity to the strategically important Strait of Gibraltar, which separates the Mediterranean Sea from the Atlantic.

Most migrants hoping to reach Spanish territory tend to head for the Canary Islands archipelago instead. They travel along a migration route considered the world's most dangerous.

Also read: How Senegalese fishermen try to reach Europe

With Reuters, AFP