UNITED NATIONS -- U.N. experts say it is "highly probable" that a deadly airstrike on a migrant detention center in Libya was carried out by a fighter jet operated by a government supporting Khalifa Hifter, who launched an offensive in April seeking to capture the capital, Tripoli.
The panel of experts said in a report to the U.N. Security Council that it "reserves identification of this member state until further physical evidence or imagery emerges to increase attribution confidence levels."
The July 3 night attack on the detention center in Tajoura near Tripoli killed more than 50 people and injured over 130 others. U.N. human rights chief Michelle Bachelet has said the attack could amount to a war crime.
The panel, which monitors sanctions against Libya, said it "continues to investigate the circumstances of the airstrikes."
The report's summary and findings on the Tajoura attack were seen late Friday by The Associated Press.
Migrants and asylum seekers "remain vulnerable not only to the effects of the conflict, but to abuse" in government detention centers, including "degrading living conditions, repeated extortion, sexual and other exploitation, and torture," the report said.
Libya became a major crossing point for migrants to Europe after the overthrow and death of longtime dictator Moammar Gadhafi in 2011, when the North African nation was thrown into chaos, armed militias proliferated and central authority collapsed.
The country was divided, with a weak U.N.-supported administration in Tripoli overseeing the country's west and a rival government in the east aligned with the self-styled Libyan National Army led by Hifter, a former Libyan army general. Each side is backed by an array of militias and armed groups fighting over resources and territory.
Hifter launched the surprise military offensive on April 4 aimed at Tripoli, with support from Egypt, the United Arab Emirates, Jordan and Russia. But he has faced stiff resistance from fighters aligned with the U.N.-recognized government, which is aided by Turkey and Qatar.
The attack on Tajoura was one of the deadliest since the conflict began.
The panel said it has "independent evidence from a reliable confidential source that an unknown number of Mirage 2000-9" fighter jets were using the al-Khadim air base in eastern Libya and the Jufra base in the north-central part of the country at the time of the Tajoura attack.
Hifter's forces don't possess such sophisticated aircraft, the panel said.
It said the Mirage 2000-9 can operate at night and deliver precision-guided munitions and missiles.
"Therefore, the panel finds it highly probable that the airstrike was conducted using PGM (precision-guided munitions) at night by a modern FGA (fighter ground attack) aircraft owned and operated by a member state, acting in support of the HAF (Hifter armed forces)," the report said.
While no country has been named, the UAE has a fleet of Mirage 2000-9 fighter jets, which are produced by France's Dassault Aviation. In November 2017, the UAE armed forces announced plans to upgrade the fleet.
As for Hifter's offensive, the U.N. experts said it has stalled reforms and sparked a new phase of instability in Libya.
The experts also said both sides in the conflict have received weapons and military equipment, technical support and "non-Libyan fighters" in violation of a U.N. arms embargo.
"Jordan, Turkey and the United Arab Emirates routinely and sometimes blatantly supplied weapons, with little effort to disguise the source," the report said. "The panel also identified the presence of Chadian and Sudanese armed groups in support of forces affiliated" to both sides.
But, the panel added, "in reality the impact of the foreign armed groups to outcomes in the conflict was limited."
"Neither side has the military capability to effectively decide the outcome to their advantage," the report said. "Consequently, fatalities among armed groups and civilians remain low."
The Security Council's 15-member committee monitoring sanctions against Libya is expected to discuss the report at the end of the month, and diplomats said in may be publicly released in December.