The Spanish government has repatriated more than 750 African migrants, including 30 children
The majority were Senegalese and were caught last week trying to enter the Canary Islands, according to Spain's interior ministry.
The government said all illegal immigrants would be expelled.
The latest influx is blamed on the temporary suspension of maritime patrols between the Spanish islands and the western coast of Africa.
The Spanish Interior Minister, Alfredo Perez Rubalcaba, confirmed the migrants had been returned home.
"We have repatriated, with the invaluable help of the government of Senegal, nearly 600 citizens of that country," he said. "This is an unmistakable message to the mafias."
Traffickers often extort money from Africans trying to reach Europe via hazardous sea crossings to the Canaries.
Spain repatriates 750 illegal migrants in week