A car bomb killed four civilians and wounded 14 others in the war-torn Libyan city of Benghazi Friday night, a hospital official said.
The car was parked in front of the entrance of the Al-Jalaa hospital, one of the two biggest in the city and where troops get treatment for injuries battling armed groups, including Islamic State militants.
Fadia Berghathi, head of the hospital's media department, told AFP "a car bomb exploded in front of the entrance of the hospital, killing four civilians and wounding 14 others".
A military source in Benghazi told AFP the explosion "was caused by a sticky bomb planted under a car parked in front of the hospital".
There was no immediate claim of responsibility.
For two years the eastern city has seen bloody battles between loyalist forces led by General Khalifa Haftar and armed groups including militants from IS group and Ansar al-Sharia, which is close to Al-Qaeda.
The hospital treats Haftar's fighters and is frequently visited by his commanders.
Pro-government forces Friday repelled a counterattack by IS group as they pressed their offensive to retake the militants' coastal bastion of Sirte, 450 kilometres (300 miles) east of the capital Tripoli.
The Western-backed overthrow of dictator Muammar Gaddafi in 2011 plunged Libya into chaos, with rival rebel forces seizing as much territory as they could.
IS Islamist militants groups have taken advantage of the upheaval to establish a presence.