The Cigala Fulgosi patrol vessel picked up the group from a makeshift craft around 75 nautical miles off the Libyan coast as part of Italy's "Mare Sicuro" ("Safe Seas") operation, the navy said.

A navy statement said those on board, including two women and eight minors, were in "mortal danger" as their vessel had taken on water, adding they had been rescued "in line with Italian and international law."

Hard right Interior Minister Matteo Salvini, currently campaigning for looming EU elections, had beforehand warned he would not allow the migrants to be disembarked in Italy.

Italy's government has taken an increasingly hard line on migration, and Salvini, head of the anti-immigrant League party, last month signed a new directive against charity vessels rescuing migrants off Libya.

Charity ships have drawn fire from Rome by attempting on occasion to stop migrants being taken back to crisis-hit Libya, which human rights organisations say is not safe for repatriations.

Amid Italian concerns that recent violence in Libya will spark an exodus of people determined to seek safety in Europe, Salvini has warned Italian ports are closed to those attempting perilous Mediterranean crossings.

Last August, dozens of migrants aboard the Italian coastguard vessel Diciotti were stranded in a Sicilian port before Salvini allowed them to disembark saying several bishops had agreed to take them in.

An accord was reached with the Catholic Church to have Ireland and Albania take some of them in.

Salvini faced a judicial investigation into his role in the initial stand-off but the Italian senate blocked a criminal case against him.

"I don't have a port available for them to disembark," Salvini told reporters Thursday on the sidelines of a campaign meeting.

"I am minister to defend borders, block traffickers, expel illegals and protect Italians."

The UN High Commissioner for Refugees and the International Organization for Migration meanwhile urged "international solidarity" to be shown to the 36 migrants, adding that returning the group to Libya in its current volatile state would violate international law.