New Delhi, Jan. 28 -- South Sudan's army, following territorial losses in recent weeks, has announced a major military operation against opposition forces, raising fears for civilian safety.

In a statement on Sunday, army spokesman Lul Ruai Koang said Operation Enduring Peace would commence and ordered civilians to evacuate three counties in Jonglei state immediately. He directed aid groups to leave within 48 hours.

Koang told The Associated Press on Monday that the operation aims to recapture towns recently seized by opposition forces and "reestablish law and order."

The announcement came a day after a senior army commander was filmed urging his troops to kill civilians and destroy property in the Jonglei offensive, drawing rebuke fro...