Egypt on Wednesday blamed organized criminal gangs of people traffickers operating on its territory after a boat carrying 500 illegal migrants was intentionally capsized off Malta.

The migrants, including up to 100 children, drowned after smugglers sank their ship when the passengers refused to change to a smaller vessel, survivors said.

A young girl was one of at least two migrants who drowned and six more were rescued when their boat sank on Friday in the Mediterranean Sea, Greek port police said.

The Philippines urged its thousands of workers in Libya on Saturday to leave the strife-torn nation now while they still can, warning that the remaining exit routes were closing fast.

A Maltese worker who was abducted by Libyan rebels on the outskirts of Tripoli on July 17 has been freed and arrived home safely in Valletta on Monday, authorities said.

Martin Galea, 40, a health and safety professional who worked for an oil and gas company, appeared to be in good health but was taken to hospital for a thorough examination.

Libyan rebels have kidnapped a Maltese worker on the outskirts of Tripoli, Malta's foreign office said Friday.

"I can confirm that we have been informed about the abduction. That is all I can say for now," a spokesman for the Foreign Office in Valletta told Agence France-Presse.

More than 800 migrants were rescued overnight while attempting to cross the Mediterranean, the Italian navy said on Monday, while five bodies were recovered in the operation. 

A group of some 130 migrants, including a baby, who were plucked from the sea off the coast of Malta after their dingy deflated, landed safety on the small Mediterranean island on Sunday, its navy said.

They were rescued overnight in an operation involving officials from Italy, Malta and the United States, who were still monitoring 25 boats packed with migrants.

Malta's Marie-Louise Coleiro Preca was on Friday sworn in as the island state's ninth president after being named by the prime minister and approved by parliament.

Coleiro Preca, a notary by profession, was previously minister for social policy after the Labor party returned to power following March 2013 elections.

Malta's navy has rescued 90 migrants attempting to cross the Mediterranean by boat, providing medical assistance to five women on board.

The migrants sent out a distress call by satellite telephone late Thursday when their boat was 25 nautical miles north of the Maltese island of Gozo, a spokesman for the Armed Forces of Malta said.

Libya's fugitive ex-prime minister Ali Zeidan has flown to Germany in defiance of a travel ban after changing planes in Malta, Maltese government sources told AFP Wednesday.

Zeidan arrived in Malta on a Libyan state plane Tuesday evening but then switched to a private jet after a brief stopover before departing for Germany, they said.