Libyan Prime Minister Baghdadi Mahmoudi has blamed Nato for opening the gate of immigration to Europe.

"The seaport in Tripoli was bombed and security guards were killed. Now the gate is wide open to illegal immigration. Now we don't have any means to stop it," he told reporters.

He was reacting to questions after a boat carrying hundreds of migrants capsized off Tripoli harbour last week. Many of those on board drowned.

The Wall Street Journal has also reported from Tripoli that Libyan security agents are confiscating money and belongings of African migrants in order to allow them onto the boats for their passage North.

At least 12,360 migrants have crossed the sea to Italy and Malta over the past few weeks, according to the International Organisation for Migration.

A spokesman for the organisation said it was troubled by the regular reports that Libyan policemen or soldiers directed African migrants to the boats after taking all their belongings.

A spokesman for the Italian foreign ministry expressed confidence that an agreement between Italy and Libya for the repatriation of migrants would be restored once stability returned to Libya.