U.S. army officials say American forces will temporarily leave Libya three days after a renewed flareup of fighting between rival armed groups.

Marine Corps Gen. Thomas Waldhauser, head of U.S. Africa Command, said in a statement Sunday "the security realities on the ground in Libya are growing increasingly complex and unpredictable."

He did not say where U.S. forces will relocate to.

Khalifa Hifter, leader of the self-styled Libyan National Army, announced Thursday his offensive on the capital city of Tripoli, the seat of Libya's U.N.-backed government, leading to fresh clashes with rival militias.

A showdown between Hifter's army and the militias could plunge Libya into another spasm of violence, possibly the worst since the 2011 civil war that toppled and later killed longtime dictator Moammar Gadhafi.