About 300 African migrants have arrived in the Spanish Canary Islands on board three small fishing boats
At least six children were on one of the vessels, and at least three people were taken to hospital suffering from exhaustion and dehydration.
It brings the estimated number of would-be immigrants arriving in the Canaries to 600 in recent days.
About 12,000 Africans have made the risky voyage to the islands this year - double the 2005 total, Spain says.
The influx has put enormous strain on the coastguards, police and rescue workers.
The first of the three vessels, carrying 97 people, arrived at Tenerife's El Confital beach in the early hours of Sunday.
A second boat with 104 people on board, including at least six children, later arrived at the nearby port of Los Cristianos.
A third vessel carrying up to 90 people travelled to the island of La Gomera.
The long and dangerous journey to the Canaries from Mauritania has in recent months become the favoured route to the European Union for migrants from Africa.
Spain and Morocco have stepped up joint efforts to prevent immigration by sea across the much shorter Strait of Gibraltar.
The European Union plans to launch maritime patrols around the Canaries and along the West African coast to help limit the flow of migrants.
On Wednesday, the bodies of 28 illegal West African migrants were found washed up on a beach in Western Sahara, according to Morocco's state-run news agency.
They had set off in two boats from Morocco in an attempt to reach the Canary Islands, it said.
A week ago, tourists on a Tenerife beach came to the aid of 88 exhausted African migrants - among 205 who reached the islands on three open boats.
And last month, four Africans were found dead in a small open boat packed with migrants, intercepted off the islands.
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