World powers and the United Nations have condemned fresh fighting in Libya as rebel forces from the east of the country march on the capital.
The G7 group of rich countries urged all parties "to immediately halt all military activity". The UN Security council issued a similar call.
Khalifa Haftar, leader of the self-styled Libyan National Army (LNA), has ordered the advance on Tripoli.
Reports suggest there is fighting near the international airport to the south.
Tripoli is the home of Libya's internationally recognised government, which has the backing of the Security Council.
UN troops in the city have been placed on high alert. Violence and division have riven Libya since long-time ruler Muammar Gaddafi was deposed and killed in 2011.
What's happening on the ground?
The LNA's leader Haftar ordered his forces to advance on Tripoli on Thursday, as UN Secretary General Antonio Guterres was in the city to discuss the ongoing crisis.
Gen Haftar spoke to Mr Guterres in Benghazi on Friday, and reportedly told him that his operation would not stop until his troops had defeated "terrorism"./BBC