It is believed many of the victims were migrants from sub—Saharan Africa, who may have been heading for Europe.
On Monday the Libyan National Army announced it would launch heavy air strikes on Tripoli.
The strikes hit a detention centre in the Tajoura suburb of the Libyan capital.
Libya is currently engulfed in civil war with the rebel LNA, led by Khalifa Haftar, attempting to seize Tripoli from the internationally recognised government.
The LNA denied responsibility for the strike, instead blaming militia loyal to Tripoli.
Earlier this week the LNA said it would launch a campaign of airstrikes as the “traditional means” of war had been exhausted.
For the past three months the LNA has been attempting to size Tripoli.
However it suffered a major blow last month when Gharyan, its main forward base, was seized by government forces.
Libya is at the centre of a migrant crisis, with thousands travelling to the country before attempting to reach Europe.
Those caught by the government are held in detention centres, and it was one of these which was hit late on Tuesday.
More to follow…