At least 24 would-be immigrants from Africa have drowned off the Mauritanian coast in West Africa after an apparent shipwreck, Spanish authorities have said.

The bodies were recovered by a Spanish hospital ship, authorities said. The Spanish government meanwhile offered Mauritania help in stemming the swelling tide of illegals leaving its coasts for Europe.

The bodies, which had life jackets on, were found floating in the sea 740 km south of the Canary Islands off the frontier between Mauritania and Moroccan-controlled Western Sahara. A fishing boat alerted the hospital ship, which retrieved 18 bodies overnight and on Wednesday. Rescuers continued combing the sea for more bodies because a vessel carrying immigrants is believed to have become shipwrecked. The influx of immigrants to the Canary Islands meanwhile continued, with the coast guard intercepting three boats carrying a total of about 150 people off Tenerife and Gran Canaria.

The previous day, around 300 immigrants reached Tenerife and Gran Canaria, the largest number in one day recorded on the islands in a decade. More than 800 Africans have reached the Canaries since the weekend, bringing the total to about 3 000 this year. Earlier this month, 45 immigrants drowned en route to the islands. The Canaries were experiencing an ?extraordinary humanitarian tragedy,? said Jose Segura, a government delegate to the archipelago.

The government announced that two senior officials would travel to Mauritania to launch an urgent cooperation plan. They were expected to offer the desert country with a 2 400-km border help in patrolling its frontiers and in establishing reception structures for immigrants.

It also agreed to increase the surveillance of the Canaries coasts and to establish new immigrant centres at military installations.

The route leading from Mauritania or Western Sahara to the Canary islands has become more popular after Spain and Morocco stepped up the fight against illegal immigration, making it more difficult for boats to make the 14-km crossing over the Straits of Gibraltar.

The 800-km sea voyage to the Canaries is more dangerous and is believed to have increased the number of casualties.