By Ayman al-Warfalli and Aidan Lewis

BENGHAZI, Libya/TUNIS March 21 (Reuters) - An eastern Libyan force says it will investigate abuses by its troops after images showing the public display of corpses and allegations of summary killings surfaced with the end of a siege in Benghazi last week.

The self-styled Libyan National Army (LNA) said dozens of its Islamist-led opponents were killed as the siege at unfinished tower blocks in the eastern city was broken on Saturday. Fighters and their families tried to escape.

Unverified photos and videos emerged on social media appearing to show LNA troops posing with corpses and parading the rotting body of a prominent opponent on a vehicle, as well as carrying out summary killings.

Eastern military figures, separate from internationally recognised officials in Tripoli in the west, present the LNA as a force that will eventually control the whole of Libya.

The LNA's general command called on unit commanders to hand over to military police all those filmed carrying out abuses. "The actions carried out by members of the Libyan National Army after the liberation of west Benghazi are considered individual acts and do not represent the instructions of the army," it said in a statement late on Monday.

"Those who committed these violations will be held accountable for their actions."



PAST ABUSES

Hanan Salah, a senior researcher on Libya for Human Rights Watch, said the LNA had failed to publicly crack down on similar abuses in the past.

"What we need to see is a real investigation - we need to see that they are arresting people, investigating them and holding them accountable," she said.

The suspected abuses raise fresh questions over the coherence of the LNA as a professional fighting body.

Its leader, Khalifa Haftar, is widely assumed to be seeking national power. He has spurned a U.N.-backed government in Tripoli that has sought to unify political and armed factions that splintered into rival camps in the east and west in 2014, three years after the overthrow of Muammar Gaddafi.

The LNA's critics say it is a loose collection of armed groups with fickle loyalties and little discipline, similar to the militias operating in western Libya.

They point to slow progress in Benghazi, where it launched an operation against Islamists and other opponents nearly three years ago, but still faces pockets of resistance.

This month the LNA suffered a setback southwest of Benghazi, losing control of two oil ports before regaining them. It says it is now pursuing its opponents, who it accuses the U.N.-backed government of supporting, in the desert region of Jufra, whilst also preparing to "liberate" Tripoli from the militias that control it.





(Reporting by Ayman al-Warfalli; Writing by Aidan Lewis; Editing by Ralph Boulton) ((Aidan.Lewis@thomsonreuters.com ; +216-29850352;))