Hundreds of migrants in distress off the Canary Islands were rescued in the span of a few hours, Spanish emergency services said on Thursday.
The Maritime Safety and Rescue Society said teams worked all night to tend to a total of 516 migrants travelling on five boats, with young children and babies among the passengers. They were mainly from sub-Saharan African countries.
The people, some in critical condition, were taken to the Atlantic islands of Tenerife, Gran Canaria and El Hierro.
Passengers told the rescuers that 10 to 12 died on one of the boats during the crossing. The bodies were thrown overboard.
Local Spanish media, including La Provincia newspaper, reported that one woman gave birth while on the boat.
There has been an uptick in the number of refugee boats arriving on Spain's Canary Islands, around 100 kilometres off the north-west coast of Africa, since last year.
The Spanish Interior Ministry said almost 21,000 migrants arrived in the country by sea in the first five months of the year, marking a 136% rise over the same period last year.
Canary Islands President Fernando Clavijo once again called for urgent action from Madrid and Brussels, calling the situation "unfair" for both the migrants seeking a new life in Europe and the citizens of his region who must bear an undue burden.