The Italian government and national energy giant ENI will send seven fire-fighting planes to help combat an inferno raging at an oil depot on the outskirts of Tripoli, Libyan authorities said Tuesday.

Italy will also send teams to help firefighters try to tackle the blaze, which was sparked during fighting Sunday night between Libyan militias and has been raging ever since, a government statement said.

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.

Libya said a second fuel depot caught fire Monday in Tripoli, in a "very dangerous" development following a huge oil tank blaze triggered by clashes around the capital's airport.

"The situation is very dangerous after a second fire broke out at another petroleum depot," the government said, warning of a "disaster with unforeseeable consequences".

Libya on Monday denied claims from Cairo that Egyptian nationals were among those killed in a rocket attack on a house in Tripoli at the weekend.

Egypt's foreign ministry had said a rocket hit a house in the capital on Saturday, killing 23 people, including several Egyptians.

Two weeks of fighting between militias in Libya's capital Tripoli have left 97 people dead, as Egypt and western foreign ministries Sunday urged their citizens to leave amid spiraling violence.

Washington evacuated its embassy staff on Saturday, with Secretary of State John Kerry warning the mission had faced a "real risk" from fierce fighting between armed groups for control of Tripoli's airport.

Germany on Sunday advised all citizens currently in Libya to immediately leave the strife-torn country as a British embassy convoy came under fire, amid measures taken by countries including Britain and the United States to protect citizens from increasing violence.

"The situation is extremely unpredictable and uncertain," the German foreign ministry said. "German nationals are at increased risk of kidnapping and attacks."

The United States evacuated its Libyan embassy staff under air cover Saturday as they faced a "real risk" from fierce fighting around Tripoli airport, Secretary of State John Kerry said.

The announcement came hours after the country's interim government warned the clashes between militia vying for control of the strategic airport were threatening to tear Libya apart.

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.

The Libyan government warned on Friday of the possibility of a break-up of the country if clashes between rival militias for control of Tripoli airport went on.

Calling for an end to 13 days of conflict around the airport, the interim government warned of "the collapse of the country" and "the destruction which could result from ... endless war."

The General National Congress, which has governed violence-wracked Libya since dictator Moammar Gadhafi's overthrow, said Wednesday it will hand over legislative power to a newly elected parliament on August 4.

But hopes that the announcement would signal an end to fighting among rival factions were dashed as a more than week-long battle intensified for control of Tripoli airport.