A Libyan hospital spokesman says nine pro-government fighters have been killed and 50 wounded in latest fighting for the Islamic State group's bastion of Sirte.

Libyan forces loyal to the unity government have been waging an offensive since last month to dislodge the militants from the coastal city.

The spokesman, Abdel-Aziz Essa, said on Wednesday that the fatalities occurred the day before and that the anti-IS group militiamen died either from sniper fire, direct gunfire or in road bomb explosions.

The fighting in Sirte, the only remaining IS group stronghold in the oil-rich North African country, started in early May. It's being led mostly by militias from the western city of Misrata, which is aligned with the U.N.-brokered government in the capital, Tripoli.

The militia offensive has slowed amid ferocious IS group resistance.