By Staff Reporter
The jet hit a block of flats near the new parliamentary building after developing a “technical fault”, a security official said.
Parliament had earlier relocated to Tobruk, more than 1,000km (620 miles) away, because of the deteriorating security situation in Tripoli.
Witnesses said the jet was flying at a low altitude and smoke was billowing out of its engine before it crashed into an apartment block and burst into flames, the AFP news agency reports.
It came down on Tuesday around 1km (0.6 miles) from the seat of parliament, killing at least two residents and a co-pilot, Reuters news agency reports.
The dead included a child, but the co-pilot survived, an unnamed security official is quoted by AFP as saying.
The militia groups, many of whom are allied to rival politicians, have been fighting for power among themselves.