A weekend police sweep in Athens led to the arrests of nearly 1,600 undocumented immigrants, officials said Monday as a minister claimed an "invasion of immigrants" threatened debt-choked Greece's foundations.

According to Monday's tallies, more than 6,000 people were questioned during the crackdown. A total of 1,595 of them were arrested and will face deportation.

Located in the southeastern extremity of the EU, Greece is the main entry point for migrants from Asia or Africa illegally crossing into the 27-state bloc.

Greece is struggling with a crippling economic crisis and swingeing austerity cuts, leading to rising social tensions, an increase in racist attacks and support for a neo-Nazi, anti-immigrant party, which won 18 of 300 seats in June parliamentary polls.

Minister for Citizen Protection Nikos Dendias said the issue of illegal immigration was "perhaps more important than the financial problem" facing Greece.

The conservative politician told Skai radio that immigrants were "a bomb at the foundations of society and the state," and said the "invasion of immigrants" had historic importance for Greece.

Evangelos Venizelos, the leader of the socialist Pasok party, which is part of the ruling left-right coalition, said the law should be respected in Athens but worried the problem would be transferred to other towns in the north of Greece.

Several Greek media outlets said most of the immigrants had been transferred to detention centers near the border with Turkey.

AFP