The UN has urged rival forces fighting near the Libyan capital to halt fighting for two hours so casualties and civilians can be evacuated.
On Sunday rebel forces under Gen Khalifa Haftar said they had carried out an air strike in southern Tripoli.
Gen Haftar’s troops have advanced from the east with the aim of taking the capital, Tripoli.
The UN-backed prime minister has accused him of attempting a coup and says rebels will be met with force.
The UN said hostilities should cease at 16:00 local time (14:00 GMT) to allow access for the emergency services.
International powers have also begun evacuating personnel from Libya amid the worsening security situation.
Libya has been torn by violence and political instability since long-time ruler Muammar Gaddafi was deposed and killed in 2011.