BENGHAZI, Libya (AP) — At least 146 people have been killed since a Libyan military commander launched an offensive on the capital earlier this month, the U.N. said Monday, as Italy called for an immediate cease-fire and the withdrawal of his forces.

The World Health Organization said 614 others have been wounded since the Field Marshal Khalifa Hifter's self-styled Libyan National Army launched its offensive on April 5. It did not specify whether those killed and wounded were civilians or fighters.

The fighting pits the LNA against rival militias loosely affiliated with a weak U.N.-backed government based in the capital, Tripoli.

The U.N. says more than 13,500 people have been displaced.

The clashes threaten to ignite civil war on the scale of the 2011 uprising that toppled and killed longtime dictator Moammar Gadhafi. The oil-rich North African country is split between rival governments in the east and west.

Italy's Prime Minister Giuseppe Conte called for an immediate cease-fire and the withdrawal of Hifter's forces, saying that a military campaign would not bring stability.

He spoke Monday after meeting with Qatar's foreign minister in Rome.

"We hope and we are working with full determination to prevent a continuation of military hostilities," Conte said, adding that he has personally intensified diplomatic contacts to reach a political solution under U.N. auspices.

"We must prevent a humanitarian crisis that would be devastating, not only for the obvious impact on our country and the European Union," Conte said. "It is also in the interest of the Libyan population. We must never forget that in cases of armed conflict, the civilians are the ones who bear the greatest consequences."

Since 2011, Libya has become a major conduit for African migrants fleeing war and poverty and seeking a better life in Europe. Italy and other European countries have provided aid to Libyan authorities to try and stem the flow of migrants.