Premier Silvio Berlusconi on Saturday defended Italy's decision to send boatloads of potential asylum seekers back to Libya and criticized the idea of a multiethnic Italian nation.

The premier, upholding his conservative coalition's crackdown on immigration, told a news conference only those who met conditions for political asylum and set foot on Italian soil would be allowed into the country. Italian territory included territorial waters, Berlusconi noted.

Previous, left-leaning governments "opened the doors to clandestine migrants coming from other countries, with an idea of an multi-ethnic Italy," Berlusconi said. That kind of society "is not our idea."

The center-left opposition blasted Berlusconi's defense of the immigration crackdown.

"Yes, Mr. Premier, we have a different idea of Italy, multiethnic, pluralistic, free," said Giovanna Melandri, a Democratic Party leader.

"A country in which the color of the skin, the race or the religion doesn't matter, but, rather, honesty and sincerity of heart do," Melandri said in a statement.

On Thursday, Italian coast guard and police boats took 227 migrants to the port of Tripoli, Libya, after they were picked up in waters Sicily and Malta. Italy contends the migrants set sail in smugglers' boats from Libyan shores.

The U.N. High Commissioner for Refugees as well as some human rights and humanitarian aid groups criticized the return, saying there may have been passengers aboard who were eligible to seek political asylum.

But Berlusconi brushed off the criticism.

"I see no scandal," Berlusconi said. "It's clear that in the sea we will lend assistance" to clandestine migrants. But when migrants were rescued in international waters Italy had the right not to take them in, he said.

Berlusconi's government allies include the anti-immigrant Northern League party. The government is trying to push through Parliament new legislation which would make it a crime to be a clandestine immigrant in Italy.

Other government plans, to make it obligatory for doctors and school principals to report illegal immigrants who come to hospitals or schools, have provoked stiff criticism, including from Vatican and other Catholic officials, as well as more centrist politicians in Berlusconi's center-right majority.