Embassies and aid workers are trying to evacuate staff from South Sudan's capital, Juba, as a precarious calm settles over the city following several days of deadly clashes.

Hundreds have been killed in the fighting that began Thursday night. President Salva Kiir and the former rebel leader, First Vice President Riek Machar, declared separate cease-fires Monday night.

The cease-fires appear to have held so far.

The fighting has severely threatened a peace deal signed last year between Kiir and Machar that brought them and their supporters into a unity government in April.

Witnesses have described government troops lining up tanks and firing on the United Nations base where tens of thousands of civilians are sheltering.

The U.S. Embassy and Doctors Without Borders are among the organizations pulling out their staffs.