The UN has said the airstrike on a migrant detention centre near Tripoli that killed at least 44 people and injured more than 130 could constitute a war crime.

The UN-recognised Government of National Accord blamed the bombing in the early hours of Wednesday morning on forces loyal to General Khalifa Haftar, head of the Libyan National Army. The LNA has denied targeting the centre.

Tajoura detention centre sits east of the Libyan capital Tripoli and housed more than 600 people.

“The fact that the coordinates of this detention facility and the knowledge that it housed civilians had been communicated to the parties to the conflict – indicates that this attack may, depending on the precise circumstances – amount to a war crime,” UN High Commissioner for Human Rights Michelle Bachelet said in a statement on Wednesday, adding that it was the second time the Tajoura centre had been hit in current hostilities, reported Efe news.

Amnesty International called on the International Criminal Court to conduct an urgent investigation and for the incident to be independently probed as a war crime.

UN Secretary-General Antonio Guterres called for an independent investigation into the incident “to ensure that the perpetrators are brought to justice” and urged a return to political dialogue.

The US’ government also asked parties to return to the discussion table.

“This tragic and needless loss of life, which impacted one of the most vulnerable populations, underscores the urgent need for all Libyan parties to de-escalate fighting in Tripoli and return to the political process, which is the only viable path to lasting peace and stability in Libya,” the State Department said in a statement.

The UN Security Council was scheduled to meet in an emergency session on Wednesday to discuss the situation.

People-smuggling gangs have grown amidst Libya’s political chaos, leading to many attempted crossings of the Mediterranean Sea, and with many migrants – often from sub-Saharan Africa – ending up in detention camps in the country, the conditions of which have been condemned by human rights agencies.

Amnesty International said the “brutal slaughter is also a sickening reminder of the deadly consequences of Libya and Europe’s callous migration policies.”

“Their cooperation to stem the flow of migrants and refugees means that instead of being offered safe routes out of the country, thousands of people intercepted in the central Mediterranean are returned to Libya where they are arbitrarily detained in centres where they are exposed to torture and mortal danger,” Amnesty’s Deputy Middle East and North Africa Director Magdalena Mughrabi said in a statement.

Bachelet in her statement reiterated her call for the closure of migrant detention centres in Libya “where UN human rights staff have documented severe overcrowding, torture, ill-treatment, forced labour, rape, and acute malnutrition, among other serious human rights violations” and repeated a call for the migrants’ urgent release.

Libya has been embroiled in violent conflict and division since Muammar Gaddafi was overthrown by NATO-backed forces and killed in 2011.