Morocco has sent the first of several planes full of illegal West African migrants to Senegal.
The migrants accuse Morocco’s security forces of ill-treating them. The flight with 140 migrants arrived from Oujda, near the Algerian border.
Hundreds of migrants were dumped there after trying to enter or being expelled from Spanish enclaves in North Africa.
Amid growing international concern, humanitarian groups have criticised Spain for expelling the migrants.
Spanish Foreign Minister Miguel Angel Moratinos is visiting Morocco to discuss the crisis as it reviews its deportations policy.
A government official in the Melilla enclave said no more deportations were planned at the moment.
The aid agency, Medecins Sans Frontieres, said on Friday it had found more than 500 migrants abandoned by Moroccan police in the Sahara desert without food or water, some of whom had been illegally expelled by Spanish police.
Twenty-eight-year-old Aboubakar Diallo from Mali said he was ready to go home after failing to make it into Melilla.
“It’s tough here . . . it’s hell on earth, lack of water, no food and live ammunition to face. We get treated like animals,” told AFP news agency.
The migrants who remain in one of the enclaves, Melilla, say their treatment at the hands of the Moroccan security forces was appalling, the BBC’s Chris Morris in Melilla says.
They have appealed to Spain not to deport anyone else back across the border.
Spain and Morocco have taken a tougher line against the migrants in the last few days, after thousands of people tried to storm the high razor wire fences which surround Melilla and Ceuta.
Hundreds of migrants made it across, but at least 11 were killed.
That prompted Spain to deport some of the new arrivals back to Morocco, a move denounced by humanitarian groups.
They say hundreds of other migrants caught on the Moroccan side of the border have been taken further south and dumped in the remote desert region near the airport at Oujda.
United Nations Secretary General Kofi Annan has urged the two governments to treat the migrant groups humanely.
The European Union and UN are sending teams to Morocco amid growing concern about how the authorities are treating immigrants.
The issue presents a big dilemma for Spain, but it could also become a political problem for the Socialist government, our correspondent says.
A new opinion poll says illegal immigration now tops the list of issues which concern Spanish voters the most.