BENGHAZI: Troops loyal to Libya’s internationally backed government launched a new offensive to seize the extremist-held city of Benghazi, as witnesses saw corpses on the streets Sunday and ambulances racing by.

Information over what was happening in Benghazi, Libya’s second-largest city, remained unclear, though a medical official at Al-Jalaa hospital, one of only two working hospitals in the city, said at least 10 people had been killed since Friday.

Benghazi has been held by the Shura Council of Benghazi Revolutionaries, an umbrella group for the city’s hard-line militias. Those militias include Ansar al-Shariah, which the U.S. blames for the September 2012 attack on the U.S. Consulate there that killed Ambassador Chris Stevens and three other Americans

Last year, renegade Gen. Khalifa Haftar led a unilateral offensive against the Benghazi militias. He formally joined ranks with Libya’s elected government on Oct. 15. Since then, they say they have managed to take control of most of the city.

Residents said Sunday that the military took control of large portions of Al-Leiti, a Benghazi neighborhood regarded as a major stronghold for the extremist militias. They said government troops patrolled the neighborhood’s streets.

An official with the special forces of the elected government said their campaign began early Saturday.

He said th air force backed up the ground troops.

He also said two men in his unit had been killed. He, as well as the hospital official, spoke on condition of anonymity.

In other developments, a port official said a strike by security guards has closed Libya’s eastern oil port of Hariga, the country’s last functioning export port apart from two offshore fields. All other ports and most oil fields have shut down due to fighting nearby or pipeline blockages by rival factions.

The guards at Hariga complained that their salaries had not been paid, preventing Greek-registered Minerva Zoe from loading 725,000 barrels of oil, the official said. The port closed Saturday morning.

The closure will lower oil output to less than 300,000 barrels a day, a fraction of the 1.6 million Libya used to pump before the 2011 uprising that toppled Moammar Gaddafi.

Hariga in Tobruk, an eastern city near the Egyptian border, used to export around 120,000 barrels a day.

The fall of oil exports to a trickle has caused a budget crisis, delaying salary payments and halting development projects and hampering the supply of drugs to hospitals.

In another sign of failing state services, several districts in the capital Tripoli saw outages for 10 hours Sunday, residents said.

Power had already gone off for six hours Saturday.

The widespread militia violence has plunged Libya into chaos less than four years after a NATO-backed uprising toppled and killed longtime dictator Moammar Gadhafi.

The country’s post-Gadhafi transition has collapsed, with two rival governments and parliaments – each backed by different militias – ruling in the country’s eastern and western regions. The elected parliament was never allowed to properly convene due to a takeover of the capital, Tripoli, by Islamist and tribal militias.

That parliament has been forced to function in Tobruk, while the pre-election parliament has declared itself legitimate and remains in Tripoli.