Unayyis warned the death toll could increase as there were scores of injured.
The International Organization for Migration (IOM) condemned the attack and called for ending arbitrary detention for migrants.
“I strongly condemn the attack that killed many migrants and refugees at the Tajoura detention center in Libya last night. Civilians should not be a target,” Antonio Vitorino, director general of IOM, said in a Twitter post.
Also, IOM’s chief of mission in Libya Othman Belbeisi said that IOM doctors and nurses described the situation as “catastrophic.”
“The targeting of civilian lives is a crime and immediate action is needed. This is another example of the suffering of migrants living in countries of crises,” he added.
Libya has remained beset by turmoil since 2011 when a bloody NATO-backed uprising led to the ouster and death of long-serving President Muammar Gaddafi after more than four decades in power.
Since then, Libya‘s stark political divisions have yielded two rival seats of power — one in Tobruk and another in Tripoli — and a host of heavily armed militia groups.
Hurriyet Daily News