The United Nations on Monday deplored an attack on a school and field hospital in southern Tripoli at the weekend which killed four doctors and a paramedic and deprived thousands of people of access to basic services.
"The United Nations Humanitarian Coordinator in Libya, Berangere Boell-Yousfi strongly condemns the disgraceful shelling on Alamain school and Zawiyah Field Hospital in Airport road, southern Tripoli," the UNSMIL mission tweeted.
In a statement, UNSMIL called on "all parties to the conflict to respect their obligations under international humanitarian law and to "end the attack of hospitals, schools and other civilian infrastructure and personnel".
The statement also urged the warring sides in the more-than-three-month-old battle for control of Tripoli to allow "the provision of basic services" and "rapid and unimpeded passage of impartial humanitarian relief, including medical missions.
The UN-backed government has blamed the forces of eastern warlord Khalifa Haftar for Saturday's attack in Tripoli's Zaway district, which it said was an air raid.
Haftar's self-styled Libyan National Army began an offensive on Tripoli in early April, but the battle lines have changed little in recent weeks.
The fighting has left 1,100 people dead and wounded more than 5,750, while over 100,000 civilians have fled their homes, according to the UN.