Fassara Keita, 26, considers himself among the fortunate. He says he was working as a security guard in his native Mali, but fled a death threat. He walked and rode buses to reach Morocco.

From there, he paid 750 euros ($1,050) last July for a ride in a small boat with 34 other immigrants, which took three days to reach Fuerteventura, one of Spain's Canary Islands.

Arriving without documentation, he was held for 39 days on Fuerteventura, received aid from the Red Cross, and then was flown to Madrid.

"I am asking for asylum. I don't know when I'll get my papers," Keita told CNN. "But I'm better off here than in Mali."

Not all are so lucky. Just this week, six Africans died trying to reach Spain. The boats are flimsy, overcrowded, the crossing perilous. Some flee danger; many others seek jobs.

The Spanish government says illegal crossings by boat reaching all Spanish shores have declined by 60 percent this year, compared with last. The decline is 67 percent for the boats specifically reaching Spain's Canary Islands this year. About 31,000 illegal immigrants arrived by boat last year to the Canaries, which lie a mere 67 miles (110 km) off the coast of northwest Africa.

Officials say the decline is due to increased patrols off the west African coast, in cooperation with the European Union and some African countries. Another factor, they say, is the planeloads of immigrants - more than 6,500 this year alone - who have been sent back to Africa.

Spanish authorities say there's still much work to do.

"As long as the boats keep coming and as long as there's even one death in the Atlantic, we must work forcefully to end clandestine immigration," said Consuelo Rumi, Spain's Secretary of State for Immigration.

Rumi said "the only ones who can be blamed" are the mafias which traffic in humans, and "trick, defraud and extort" the immigrants when offering the clandestine boat rides.

In Madrid, the Roman Catholic Church supports a center catering to African immigrants. It is called Karibu, which means "welcome" in Swahili, said Karibu director Antonio Diaz de Freijo. Diaz de Freijo worked for 12 years as missionary in Africa before helping to start Karibu 20 years ago.

As many as 4,000 African immigrants a year get clothing, food, medical attention and advice at Karibu. But the director says what they really need are working papers.

"The people we serve can't work and fully integrate into society," Diaz de Freijo said. "That's what separates sub-Saharan Africans here from other immigrants."

A Spanish government amnesty two years ago allowed 600,000 illegal immigrants to become legal. But some experts say many sub-Saharan Africans were left out, because they didn't have even the basic documentation to present to authorities.

Immigrants from Latin America, Eastern Europe and Africa now make up nine percent of Spain's population of 45 million. Morocco and Romania are the leading sources, with more than 500,000 immigrants from each nation, while Ecuador has sent more than 400,000.

The total number of immigrants from the combined, numerous sub-Saharan African countries is far less, but their plight on the boats has sparked a great deal of media attention, some experts say.

Spanish Prime Minister Jose Luis Rodriguez Zapatero is due to speak about immigration at a summit meeting of European Union and Africa nations this weekend in Lisbon, his office said in a statement.

Zapatero is expected to propose a European-African pact based on three principals: developing employment and opportunities for young Africans to help them remain at home; a policy of managing legal migration that includes developing infrastructure as a key to growth, and a firm policy against the clandestine trafficking of illegal immigrants.

In Madrid at the Karibu center, a motorcycle mechanic from Liberia, who gave his name only as Charles, told CNN he'd rather try to get official paperwork to remain in Spain than return home.

"Going back to my country, that is going to be the most difficult," Charles said. "I prefer to live this kind of life in Spain."