Two days after a massive sweep operation in which Greek police netted over 1,000 clandestine immigrants in central Athens, Public Order and Citizens' Protection Minister Nikos Dendias defended the campaign saying failure to crack down on illegal immigration would lead to social “collapse.”

“Our social fabric is in danger of unraveling. The immigration problem is perhaps even bigger than the financial one,” Dendias told Skai radio on Monday.

He said the “invasion of immigrants” was the biggest Greece has faced since the invasion of the Dorians.

It is believed that in around 1100 BC the Dorians, a Hellenic group, swept down from the north of present-day Greece putting an end to the Mycenaean civilization.

Police said a total of 4,900 people were rounded up in Athens on Saturday in an operation to evict undocumented immigrants. Some 1,130 of them were detained.

The operation was controversially code named Xenios Zeus after the ancient Greek patron of hospitality and guests. Dendias defended the name saying the campaign was also designed to restore the basic human rights of immigrant people in Greece.

“The way illegal immigrants lived they had no human rights. They were crammed in rundown, unhealthy basement apartments. They were conned by smuggling rings into believing they would be able to get a job and travel to Europe,” Dendias said.

“Now they will return to their home countries... It's the best thing that could happen to them,” he said.

The minister said about 8,000 migrants have already made applications to leave the country under Greece's voluntary repatriation scheme.

Situated at the southeastern border of the European Union, Greece has become a popular transit point for migrants from Asia or Africa hoping to sneak into the more affluent bloc.

Current figures show Greece has about 800,000 legally-registered immigrants, while the number of those without papers is estimated at more than 350,000.