Gen. Khalifa Haftar’s Libyan National Army (LNA) attacked migrants trapped in a detention center on the outskirts of Tripoli, killing at least six and injuring 11 others, the internationally-recognized government and detainees claimed on Tuesday.

On Wednesday, human rights group Amnesty International reported that the attack, which it described as “utterly reprehensible,” amounts to “serious violations of international humanitarian law and constitute war crimes.”

Magdalena Mughrabi, the deputy Middle East and North Africa director at Amnesty International, declared:

There can be no justification for targeting defenseless civilians. These refugees and migrants should not even be detained in the first place. This incident demonstrates the urgent need for all refugees and migrants to be immediately released from these horrific detention centers where they are held arbitrarily in inhuman conditions and routinely subjected to abuse.

“Right now they are attacking the center, shooting more people … They are shooting us directly,” an unnamed Eritrean man told Al Jazeera via the messaging service WhatsApp, referring to the assault on the Qasr Ben Ghashir facility on Tuesday.

“We need medical treatment right now because the people with us, their injuries are really a lot,” he added.

On April 4, Haftar launched an offensive to take Tripoli from the United Nations-brokered Government of National Accord (GNA) headquartered there. Haftar claims the GNA enjoys support from jihadis.

The warlord has gained control of most of Libya with the help of Russia, France, Egypt, Saudi Arabia, and the United Arab Emirates (UAE).

GNA officials and Amnesty International say people held at the Qasr Ben Ghashir detention facility and other prisons in and around Tripoli find themselves caught in the middle of the fighting between the two sides.

“The reasons behind the attack remain unclear and the identity of the perpetrators is yet to be established,” Amnesty claimed.

Turkey’s state-run Anadolu Agency (AA) and Al Jazeera, citing the GNA and the victims, respectively, reported that Haftar’s LNA was behind the attack.

Mustafa el-Mecei, the spokesman for the GNA’s anti-LNA offensive, told AA that Haftar’s troops attacked the detention center for “irregular migrants in southern Tripoli’s Qasr bin Ghashir district.”

“He said six irregular migrants were killed and 11 others were wounded, adding their nationalities were not clear because they did not possess any official documents,” the news agency added.

The LNA is fighting on behalf of the breakaway government based in eastern Libya’s Tobruk region. Haftar has surfaced as the top rival of GNA Prime Minister Fayez al-Sarraj.

Al Jazeera noted:

Refugees and migrants trapped in a detention centre on the front line of conflict in Tripoli for weeks say they were shot at indiscriminately on Tuesday by fighters aligned with eastern forces advancing on Libya’s capital. … Four people in the detention centre in Qasr bin Ghashir, 25km [15.5 miles] south of Tripoli, said the fighters that attacked them were aligned with the Libyan National Army led by renegade commander Khalifa Haftar whose forces attacked Libya’s capital on April 4.

On Tuesday, Stephane Dujarric, a spokesman for the U.N. secretary-general, acknowledged that the detention center was “breached by armed actors,” without identifying the culprits, the Associated Press (AP) reported.

She added that the facility is holding some 890 refugees and migrants.

AP revealed:

The U.N. says [a total of] some 3,600 refugees and migrants are held in facilities near the front lines of fighting between the self-styled Libyan National Army and other heavily-armed militias. Five detention centers are in areas already engulfed by fighting, while six more are in close proximity to the clashes.

“The situation in these detention centers is increasingly desperate, with reports of guards abandoning their posts and leaving people trapped inside,” Dujarric declared, stressing that one facility has been without drinking water for days.

According to the World Health Organization (WHO), the fighting in Tripoli has already killed 270 people, including civilians, and injured nearly 1,300 others. The offensive has also displaced around 30,000 people.

Libya has descended into disarray since the U.S. and NATO-backed overthrow and subsequent execution of dictator Muammar Gaddafi, with two governments competing for power and jihadi groups like the Islamic State (ISIS/ISIL) taking advantage of the chaos.

The North African country has become a prominent transit point for African migrants and refugees seeking to reach Europe.

Armed groups operating some of the detentions centers often subject detainees to brutal treatment, including slavery.

“Since renegade military commander Khalifa Haftar, a strongman in Libya’s east, and his Libyan National Army advanced on Tripoli on April 4, migrants have again been treated as a bargaining chip between politicians,” Al Jazeera noted.

Noting that the United States has long supported the GNA, officials from the previous administration accused U.S. President Donald Trump of sending mixed messages when he recently spoke directly with warlord Haftar and praised his “significant role in fighting terrorism and securing Libya’s oil resources,” the Washington Times reported.