The U.N. envoy to Libya has expressed shock after bodies of 14 people, apparently victims of extrajudicial killings, were found dumped in the eastern city of Benghazi this week.

Martin Kobler is urging authorities to investigate. He posted on his Twitter account on Friday that he is "utterly shocked and dismayed by the summary execution," which he called a war crime.

Libya's al-Wasat daily says the bodies were found in a garbage dump in Benghazi on Thursday.

For the past two years, Benghazi has been convulsed with fighting between forces led by Brig. Gen. Khalifa Hifter and a coalition of Islamic militias.

Libya has slid into chaos after the 2011 ouster of Moammar Gadhafi and has in the past years become bitterly divided between rival factions and competing governments.