An international rights group has expressed alarm over the fate of hundreds of Libyan and foreign nationals trapped for months amid fighting in the eastern city of Benghazi.

Amnesty International said on Thursday that nearly 130 families and hundreds of foreigners in the southwestern Benghazi neighborhood of Ganfouda have been cut off from the outside world, with dwindling food and fuel supplies.

"Time is running out for civilians in Ganfouda, who are being left to die trapped by the fighting," said Magdalena Mughrabi of Amnesty.

The fighting has raged in Benghazi since 2014 when forces commanded by powerful military commander Khalifa Hifter began a campaign against militants there, including branches of al-Qaida and the Islamic State group.