Italy has repatriated some 180 illegal migrants following mass landings of boat people on the tiny Italian island of Lampedusa, off North Africa.
Two chartered planes flew them back to Libya, the country they had allegedly departed from, on Tuesday.
But the Italian chapter of Amnesty International has strongly criticised the move, saying it was a violation of Italian and international law.
Over 1,000 migrants have reportedly arrived at the island in 48 hours.
"The people deported today were not properly identified," Amnesty said in a statement.
"They were not informed on their right to request asylum in Italy, and were not able to do so if they wanted."
Despite the forced repatriation, the island's reception centre, designed for some 200 people, is still housing more than 700.
Lampedusa's mayor, Bruno Siragusa, appealed to the EU.
"Help us, the centre is exploding," he was quoted as saying by Italian newspaper La Gazetta del Mezzogiorno.
"Lend us a hand to tackle an emergency that is not only our island's, but Europe's as a whole."
Italy has an agreement with Libya to deport illegal migrants, and hundreds have been sent back previously.