Two German navy ships on Friday rescued nearly 400 migrants attempting to cross the Mediterranean to Europe, the defense ministry said, days after it joined a beefed-up EU mission.

In the first operation, the German frigate Hessen went to the aid of a stricken wooden vessel carrying roughly 200 migrants, about 250 kilometers (155 miles) south of the Italian island of Lampedusa.

A British navy ship on Thursday came to the rescue of around 100 migrants adrift on a dinghy in the Mediterranean, Italy's coastguard said.

The "Bulwark" was first on the scene after the International Organisation for Migration received a distress call from a migrant boat that got into trouble off the coast of Libya.

President Abdel Fattah al-Sisi said Egypt had "rescued" 27 Ethiopians from war-torn Libya, as state television showed him greeting the group at Cairo airport on Thursday.

It was not immediately clear how the Ethiopians were rescued, but Sisi's office said the group flown in on an Egyptian plane was "liberated by Egyptian and Libyan security services".

The Italian navy announced Thursday it had located the sunken wreck of a migrant boat in which 700 people are feared to have died last month.

The boat was found 85 miles off the Libyan coast at a depth of 375 meters, the navy said in a statement.

Around 40 migrants died when their inflatable boat sank off the coast of Italy, which Tuesday renewed an appeal to the EU for help in managing a relentless wave of arrivals.

Survivors of the tragedy reported 137 people were on the vessel when it either deflated or exploded shortly before a spate of rescue operations this weekend that saw the Italian navy and coastguard save almost 6,000 people on the sea. 

Thousands of illegal migrants who have tried to reach Europe from conflict-plagued Libya are being held in detention centers in the North African country, an official said on Monday.

Most are Africans intercepted off Libyan shores or inside the country as they prepared to board boats for Europe, Mohammed Abdelsalam al-Kuwiri said.

Prime Minister Tony Abbott on Monday said Australia and Europe were in talks on how to stop asylum-seeker boats after the success of his government's controversial polices on the issue.

Another 5,800 migrants desperate to reach Europe were rescued this weekend as they tried to cross the Mediterranean, more than 2,150 of them on Sunday, the Italian coastguard said.

Another 5,800 migrants desperate to reach Europe were rescued this weekend as they tried to cross the Mediterranean on rickety boats, more than 2,150 of them on Sunday, the Italian coastguard said.

The number rescued this weekend was one of the highest recorded in recent years, raising fears that the tide of people risking their lives to reach Europe from Africa and the Middle East has not been slowed by recent disasters.

Libya's coastguard on Sunday intercepted five boats carrying around 500 illegal migrants who were trying to reach Europe, an official said.

Colonel Reda Issa told AFP that most of the migrants were Africans who had set off from an unspecified location.

Italy's coastguard attempted to rescue more migrants in the Mediterranean Sunday after nearly 3,700 were picked up trying to reach Europe on Saturday alone.

Although it was not a record, the number saved was one of the highest ever recorded in a single day, and raised fears that the tide of desperate people trying to reach Europe has not been slowed by recent disasters.