Spanish efforts to repatriate hundreds of illegal immigrants to Senegal have been halted, after Senegalese authorities complained those sent back have been mistreated. Illegal immigration is shaping into a major dilemma for Spain.

Would-be immigrants sit near port of Los Cristianos, on Spanish Canary Island of Tenerife (file photo)

More than 7,000 African migrants have arrived on Spain's Canary Islands this year, a huge increase from 2005. They are the lucky ones.

Hundreds more have died trying to make their way to Spain from Africa, with Senegal becoming the new debarkation point of choice.

Spain has begun deporting these illegal immigrants back to Africa. But Senegalese authorities now say they will not accept new deportations because some of the immigrants have reportedly been mistreated.

Coordinator for domestic policy at Amnesty International in Madrid, Beatriz Gonzalez, says she does not know yet if these reports are true. But she says Amnesty is concerned about any European policy to repatriate illegal immigrants to Africa.

 "Amnesty is concerned about the transfer of responsibility in terms of migration control from the European Union to third countries like Mauritania, Senegal, Morocco. And in this context, the organization has expressed concern previously that returns have been done using an excessive use of force," she said.

The huge flood of immigrants this year has caught Spain in a bind. If officials in the Canary Islands are unable to determine where they come from, Spanish policy stipulates they must fly them to Spain where they are released in large cities like Barcelona.

But University of Barcelona political scientist Pere Vilanova says it is not just Spain's problem.

"This is a dilemma for any democratic government, which is how to combine a humanitarian approach to the problem and to control the flow of immigration. But it is not only the problem of Spain, it is the problem of the European Union," he said.

The European Union has pledged to help Madrid intercept African immigrants bound for Spain. Those who reach Spanish shores often continue on to other parts of Europe.

Meanwhile, Spain is mixing its tough deportation policy with initiatives to stop illegal immigration in the first place. Spanish officials say Madrid plans on increasing development assistance to Africa, so would-be immigrants have a reason to stay home.