At least 45 people were killed and scores injured in an airstrike carried out by eastern Libyan forces led by commander Khalifa Haftar in the country’s southwest on Sunday, according to local media.
More than 55 people including women and children were injured in the airstrike, local media reported.
Al-Ahrar TV channel earlier put the death toll at 20, citing local lawmaker Rahma Adem.
The MP said that the attack took place in Murzuq town and all the victims were from Tebu tribe.
However, Murzuq's Municipal Councilor Mohammed Omar said there was no loss of life and property in the attack targeting Tebu tribe
For its part, the Tripoli-based Libyan Presidential Council blamed Haftar’s forces for the attack, which reportedly targeted a wedding procession.
In a statement, the council called upon the UN mission and the international community to “shoulder their responsibilities, investigate the crimes committed by the Haftar forces and prosecute those responsible”.
It went on to call on Libyans to “pay attention to Haftar's attempt to ignite sedition between components of Libyan society”.
No statement was made by Haftar’s forces regarding the accusation.
The EU Commission called on Haftar’s forces to end "indiscriminate attacks" immediately.
"The air strike in Murzuq has claimed the lives of civilians in southern Libya, a region that is already paying a heavy price for the inability of the warring parties to end the crisis," it said in a statement.
"Indiscriminate attacks on densely populated residential areas may amount to war crimes and must cease immediately," it added.
The Commission also called on Libyans to support the UN special representative's attempts to relaunch political negotiations and implement a truce on the occasion of the Eid al-Adha.
Since early April, forces loyal to Haftar have been launching a campaign to capture the capital, Tripoli, from forces aligned with the UN-recognized Government of National Accord (GNA).
Clashes between the two sides since then have left more than 1,000 people dead and about 5,500 wounded, according to the World Health Organization (WHO).
Libya has remained beset by turmoil since 2011, when long-time ruler Muammar Gaddafi was ousted and killed in a bloody NATO-backed uprising after four decades in power.
The oil-rich country has since seen the emergence of two rival seats of power: one in eastern Libya, with which Haftar is affiliated, and the Tripoli-based GNA, which enjoys UN recognition.
By Ahmed Abdelmonem Khalifa Abdelbaky, Enes Canli and Hacer Baser in Tripoli, Libya