Forces loyal to the the internationally recognized government in Tripoli conducted air strikes to try to halt a march on the capital by strongman Khalifa Haftar’s troops, officials said.

Fighter jets struck positions near Tripoli held by Haftar’s self-styled Libyan National Army on Friday and Saturday, LNA media official Aguila Saber and local city official Hamed al Nuwaiser said by phone.

Haftar, a military leader whose stronghold is in the east of the country and whose forces swept through the south in January, ordered his troops on Wednesday to march on the capital. The move sharply escalated tensions in the North African OPEC state and drew rebukes from the United States and European countries.

Diplomats fear the assault could drag Libya into a bloody civil war. Its timing, as United Nations Secretary General Antonio Guterres was in the country to prepare for an April 14 political conference, shocked even Haftar’s foreign backers, who include France and the United Arab Emirates.

— With assistance by Samer Al-Atrush