BARCELONA, Spain (AFP) — Five migrants were found dead on a crowded boat that was spotted adrift south of Spain’s Canary Islands in the Atlantic, the country’s maritime rescue service said Thursday.

Rescuers were alerted on Wednesday afternoon to the vessel drifting some 800 kilometres (500 miles) south of the island of Tenerife, and a boat dispatched to the area rescued 68 people and found five bodies on board, the service said in a statement.

The boat also retrieved three bodies from the migrant vessel but had to leave it adrift with the other two bodies “due to bad weather conditions in the area,” the statement said.

Spain is one of the main gateways for migrants seeking a better life in Europe, with the vast majority making the perilous journey to try and reach the Canary Islands which lie off the northwestern coast of Africa.

The Atlantic route is particularly dangerous due to strong currents, with migrants travelling in overloaded, often unseaworthy, boats without enough drinking water.

But it has grown in popularity due to increased vigilance in the Mediterranean.

At their closest point, the islands lie 100 kilometres (60 miles) off the coast of North Africa.

But many boats — often long wooden vessels known as pirogues — leave from much further away, setting sail from Morocco, Western Sahara and Mauritania.

Increasingly they are coming from countries further south such as Gambia and Senegal which lie about 1,500 kilometres (about 1,000 miles) from the Spanish islands.

More than 5,000 migrants died while trying to reach Spain by sea in the first five months of this year, or the equivalent of 33 deaths per day, according to Caminando Fronteras, a Spanish charity which alerts the maritime authorities to migrant boats in distress.

That is the highest daily number of deaths since it began collating figures in 2007.

The vast majority were on the Atlantic route, where 4,800 migrants died while trying to reach the Canaries, the charity said.