Doctors Without Borders (MSF) said Monday that 26 of its staff were "unaccounted for" after a surge in violence in South Sudan in recent weeks.
"Twenty-six of the 291 MSF colleagues working in Lankien and Pieri remain unaccounted for following the recent violence, and we have lost contact with them amid ongoing insecurity," the NGO said in a statement.
MSF has suspended medical services in Lankien and Pieri, both in Jonglei state which has seen major clashes between government and opposition forces since December, AFP reported.
An MSF facility in Lankien was hit by a government air strike on February 3, the NGO said.
"Many of our staff were forced to flee the violence alongside their families. Several are now displaced, sheltering in remote areas with little access to food, water or basic services," the statement added.
South Sudan, the world's youngest country, has been beset by civil war, poverty and massive corruption since it was formed in 2011.
The United Nations warns of a return to "all-out civil war" as a power-sharing deal between President Salva Kiir and his long-time rival, Riek Machar, has unravelled over the past year.
Recent fighting has focused on Jonglei, but the UN said on Sunday that surging violence in Abiemnom, near the Sudan border, had killed "dozens of civilians and some local officials".
