Libya's foreign minister on Tuesday renewed the country's call for the lifting of an arms embargo and for international air strikes to help tackle the Islamic State group which threatens to create a "rear base" in the country.

"The situation is extremely serious," Mohamed al-Dayri, foreign minister for Libya's internationally-recognized government based in Tobruk, told AFP during a visit to Paris.

Around 5,300 migrants, mainly from Sub-Saharan Africa, were rescued in the Mediterranean off the Libyan coast last week, EU border agency Frontex said Tuesday.

Most were rescued over the weekend, plucked from wooden or rubber boats, in one of the busiest three-day periods since the Frontex-coordinated operation Triton was launched in November 2014.

A 15-year-old Somalian who survived beatings and forced labor in Libya died on the final stretch of his journey to Europe, Doctors Without Borders (MSF) said Tuesday.

The teenager, who had suffered beatings and been constrained to do heavy labor without adequate food or water, was chronically ill when he was rescued from a people smuggler's boat on Sunday, the medical charity said.

Italy's coastguard and navy rescued more than 1,200 migrants in the Mediterranean on Saturday after responding to multiple distress calls from 18 overcrowded vessels carrying an estimated total of 2,000-3,000 people.

Two navy patrol ships, the Cigala Fulgosi and the Vega, picked up respective totals of 507 and 432 migrants from two boats in danger of sinking just off Libya while coastguard vessels had safely boarded just under 300 people from three different inflatable dinghies.

The Arab League called Tuesday for an "urgent" Arab strategy to militarily back Libya's government against the Islamic State group, but stopped short of endorsing air strikes against the jihadists.

The Cairo-based Arab bloc issued its call after an extraordinary meeting to discuss a request by the internationally recognized Libyan government to adopt measures to confront IS which has seized the coastal city of Sirte.

Libya's internationally recognized prime minister, Abdullah al-Thani, has withdrawn an offer to resign, a move which would have added to the chaos in the conflict-strewn country, his spokesman said Monday.

"The prime minister didn't submit his resignation. He backed down from his previous announcement," Hatem el-Ouraybi told AFP.

More than 300 survivors of the latest Mediterranean migrants boat tragedy arrived in Sicily on Monday aboard a Norwegian ship also carrying the bodies of 49 of its victims.

The "Siem Pilot" docked at the port of Catania shortly after 11H00 (09H00 GMT) and an hour later the first batch of survivors began making their way tentatively down gangways on the side of the giant red vessel.

Italy warned Monday that Libya risked turning into "another Somalia" as it signed a joint statement with the U.S. and several European allies condemning "barbaric" acts carried out by the Islamic State group there.

Foreign Minister Paolo Gentiloni said if peace talks did not succeed in ending the country's civil war within a few weeks, "we will find ourselves with another Somalia two steps from our coasts".

Libya's internationally recognized government has called on Arab countries to bomb Islamic State group targets in Sirte, after warnings of a "massacre" in the coastal city.

"We urge fellow Arab countries... to launch air strikes on Daesh terrorist group positions," the government based in the country's east said in a statement on its Facebook page on Saturday, using an Arabic acronym for IS.

Islamic State group jihadists have beheaded 12 people and hung them on crosses during a battle for the coastal city of Sirte, the national news agency LANA reported Saturday.

The fighting for control of Sirte, hometown of slain dictator Moammar Gadhafi, has been raging since Tuesday, with one top Libyan diplomat warning of a "massacre" in the city.