More than 300 Africans including women and children are feared to have drowned after their boats capsized off Libya during a new upsurge of illegal migration to Europe, officials said.

At least 23 bodies of drowned migrants were recovered by Libyan coastguards near the wreckage of three rickety boats which sailed from the coastal village of Sidi Belal near Tripoli, Libya's most influential daily, Oea, said on Tuesday, quoting security officials.

One of the boats was carrying 365 people although it was only supposed to hold 75, Libyan officials said. It was one of four migrant ships which sailed from Libya between Saturday and Sunday, apparently heading for Italy.

"After more than two days of searching, we have found no more bodies or survivors or the boat," a Libyan official said.

Among those missing were people from Somalia, Nigeria, Eritrea, Kurdish areas of Syria, Algeria, Morocco, the Palestinian territories and Tunisia, officials said.

A Libyan security official quoted a Tunisian survivor as saying: "I was on board the boat with 13 other Tunisians among the 365 migrants. I'm the only survivor. All my fellow Tunisians drowned."

A fourth ship crammed with more than 350 migrants broke down near Libya's offshore Buri oilfield but Libyan coastguards towed the vessel to the port of Tripoli and rescued all the migrants, including women and children.

THREE BOATS SUNK

"Up to three boats appear to have sunk off the Libyan coast. These boats have no life-saving material on board. It would seem that more than 300 people have disappeared at sea," International Office of Migration spokesman Jean-Philippe Chauzy told Reuters in Geneva.

"They were not at swimming distance from shore," he said. IOM was not aware of any survivors aboard the three boats.

"There's no safety equipment on those boats -- no buoys, dinghies or anything -- because the purpose is to cram as many people on those boats as possible with total disrespect for their safety and dignity," Chauzy later told a news briefing.

There had been "massive departures" from Libya in the past 36 hours, amid strong sandstorms known as ghibli, according to IOM.

"Some people reached Italy, some were intercepted and brought back to Libya and some were among the people feared dead," IOM spokeswoman Jemini Pandya said.

"We'll never have a real idea of how many people were on the boats since you never really retrieve all the bodies," she said.

The boats sank near oil platforms off Libya's coast.

U.N. High Commissioner for Refugees Antonio Guterres regretted the incident, which marked the beginning of "smuggling season" in the Mediterranean, spokesman Ron Redmond said.

Guterres, a former prime minister of Portugal, described it as "the latest tragic example of a global phenomenon in which desperate people take desperate measures to escape conflict, persecution and poverty in search of a better life."

A UNHCR team was on its way to interview some of the migrants who had been sent back to detention centres near Tripoli, according to Redmond.

There are an estimated 1-1.5 million African irregular migrants in Libya, drawn by the need for unskilled labour, according to IOM. It is both a transit and a destination country for migrants.

Most come from West Africa, including Mali, Burkina Faso, Ghana, Niger, Nigeria and Ivory Coast, or from Horn of Africa countries led by Somalia and Ethiopia.

"An unknown percentage of them continue their migratory voyage towards Europe. They save their money in Libya to pay off networks of traffickers," Chauzy said.

"These people must have been heading to Lampedusa," he added, referring to the Italian island where 37,000 migrants arrived last year, most after setting off from the Libyan coast.

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