FILE -- In this March 18, 2015 photo file photo, Gen. Khalifa Hifter speaks during an interview with The Associated Press, in al-Marj, Libya. Human Rights Watch in a March 22, 2017 report is urging the powerful general in eastern Libya to investigate allegations that his forces committed war crimes such as killing prisoners and desecrating bodies. (AP Photo/Mohammed El-Sheikhy, File)

CAIRO - Human Rights Watch urged a powerful general in eastern Libya on Wednesday to investigate allegations that his forces committed war crimes such as killing prisoners and desecrating bodies.

Relatives, activists, and local journalists described such acts by troops under the command of Field Marshal Khalifa Hifter in the eastern city of Benghazi on and around March 18, the group said in a statement.

"The Libyan National Army's leadership needs to respond urgently to these deeply disturbing allegations by investigating the suspected perpetrators, including senior military commanders who may bear individual responsibility," said Joe Stork, Middle East and North Africa deputy director at Human Rights Watch.

Libya sank into chaos following the 2011 uprising that toppled and killed dictator Moammar Gadhafi, and has remained split between rival parliaments and governments in the east and west, each backed by a set of militias, tribes and political factions.

Hifter's self-styled national army is composed of Gadhafi-era officers, remains of the national military and civilians-turned-fighters. The force is backed and armed by neighbouring Egypt, which sees Hifter as its ally in a fight against Islamic militants, and is increasingly supported by Russia.

Last week it retook two key oil terminals that had been seized by militias loyal to the rival government based in the Libyan capital, Tripoli, driving out fighters, including some opponents from Benghazi he had been fighting in a long-running standoff.

Following the rout, civilians fled Benghazi's Ganfouda neighbourhood, and relatives told Human Rights Watch that some were captured and gunned down.

Videos and photos that the group saw by family members of victims, local journalists, and activists purported to show bodies of fighters in Benghazi allegedly desecrated and mutilated by the army. Another video showed a known commander, Mahmoud al-Warfalli, shooting three men in the head who had been lined up against a wall.

The army later said in a statement that it would arrest those suspected of the violations and bring them before an investigative committee, but the New York-based rights group said many of its leaders also put out statements defending the actions.

"Forces under the Libyan National Army have been committing serious human rights violations for some time, unchecked, and with impunity," Stork said. "Senior military commanders need to know that they too can be held accountable unless they actively do something to stop these violations."

Hifter's army backs Libya's last elected parliament, which was driven out of Tripoli in 2015 when Islamist-leaning militias and militias from the city of Misrata took over the capital in a blitz. The parliament is now based in the eastern city of Tobruk, and the interim government based on it is in the nearby city of Beida. They both oppose the United Nations-backed government in Tripoli.

News from © The Associated Press, 2017