"Swani field hospital was the target of an air raid that injured three ambulance workers and a rescue doctor," said Lamine al-Hashemi, a spokesman for the health ministry run by the Government of National Accord (GNA).

He told AFP that equipment at the hospital south of the capital had been damaged in the raid.

"Although it's outside the combat zone, this was the second time that the Swani hospital has been hit" since military strongman Khalifa Haftar launched an assault on April 4 to seize Tripoli from the GNA, said ministry official Fawzi Ounis.

Humanitarian organisations have called on both sides in the conflict to spare medical personnel.

Haftar's campaign to wrestle Tripoli from pro-GNA forces has left nearly 1,093 people dead, including 106 civilians, and over 5,750 wounded, the UN's World Health Organization said Monday in an updated casualty toll.

The fighting has also forced more than 100,000 people to flee their homes.