Updated

The U.N. envoy to Libya has condemned a suspected militia attack on an air base in the country's south that reportedly killed at least 60 soldiers and civilians and wounded dozens.

Martin Kobler expressed his outrage over the attack in a statement released Friday.

He suggested that if the reports were true, the "unprovoked attack on the Buraq al-Shati air base" on Thursday could amount to war crimes and may be prosecuted by the International Criminal Court.

Libya's army, loyal to an east-based parliament, promised a "strong" response to the attack, believed to have been carried out by militias from the country's west.

Libya descended into chaos following the 2011 civil war that toppled and killed dictator Moammar Gadhafi. The oil-rich nation is now split between rival governments and militias.