Three killed in Libya plane crash
The plane, carrying a pilot and two co-pilots who were killed, crashed minutes after taking off from the al-Sharara oil field, a source told AFP.
"It had arrived from Tripoli to bring supplies to the (oil) field staff and left empty," the source said.
"The captain and his two co-pilots died in the crash."
One member of the crew survived the wreck but was "seriously injured", the source added.
The cause of the crash remains unknown. Al-Sharara is one of Libya's biggest oil fields in the south of the country.
Libya has been wracked by chaos since the 2011 uprising that toppled and killed long-time dictator Muammar Gaddafi, with rival authorities and militias battling for control of its oil riches.