"First group of passengers, consisting of women and children, being released now," he said on Twitter.
"Informed of potential hijack situation of a Libya internal flight diverted to Malta. Security and emergency operations standing by -JM," the premier said in a post from his official account.
Maltese government sources told AFP there were 118 people on board the plane, including seven crew.
Maltese media reported that the hijacked plane was an Airbus 320 that had been on a domestic Libyan flight operated by Afriqiyah Airways.
Libya has been in a state of chaos since the 2011 overthrow of Moamer Kadhafi left warring militias battling for control of different parts of the country.
Forces loyal to a fledgling national unity government recently took control of the coastal city of Sirte, which had been a bastion for the Islamic State group since June 2015.
Western powers have pinned their hopes of containing jihadism in the energy-rich North African state on the government but it has failed to establish its authority over all of the country.
A rival authority rules the country's far east, backed by the forces under military strongman Marshal Khalifa Haftar, who have been battling jihadists in second city Benghazi.
