An air strike killed at least 40 people after hitting a migrant detention centre in a suburb of Tripoli, Libya, officials said.
Malek Mersek, a spokesman for a state emergency medical services, told Reuters that 40 people had been killed and 80 wounded in the strike.
A spokesman for the security services, Osama Ali, confirmed the event to AFP and said that at least 120 migrants had been held in the hangar worst hit by the air strike.
Libya has been a key departure point for migrants from Africa attempting to reach Europe by boat. Up to 90 per cent of people attempting to cross the Mediterranean Sea to Europe depart from Libya, the UN refugee agency says.
Many of these migrants are fleeing violence and poverty in their own countries.
The UN refugee agency in Libya tweeted they were "extremely concerned" about airstrikes targeting "civilians".
Libya has endured conflict and instability since the NATO-backed overthrow of Muammar Gaddafi in 2011. Three months ago, military strongman Khalifa Haftar launched a ground offensive to take Tripoli from the internationally recognised government.
The suburb where the migrant centre is located to the east of Tripoli is home to several military camps which have been targeted recently by air strikes.
On Monday, Haftar's self-proclaimed "Libyan National Army" said it would strike targets in Tripoli after "traditional means" of war had been exhausted.
Read more about the conflict in Libya here.