Military forces loyal to Libya's eastern government say Islamic State fighters have retreated from positions close to the port city of Derna.

The fighters claimed credit for Wednesday's ISIL withdrawal from positions around Derna. 

A spokesperson for the military forces also said they carried out airstrikes overnight Thursday against an Islamist group known as the Derna Mujahideen Shura Council, who also claimed credit for ISIL's withdrawal.

Derna was an early bastion for ISIL militants returning from Iraq and Syria.

Last June, the Shura Council forces pushed them out of the city. Derna has since been the site of a three-way conflict between the council, forces loyal to the eastern government, and ISIL jihadists.