Libyan pro-government forces on Monday battled jihadists from the Islamic State group in second city Benghazi, where five pro-government fighters have been killed in two days of violence, media said.
Four loyalist soldiers died and 22 were wounded on Sunday in clashes with IS in the southern district of Hawari, the pro-government LANA news agency reported.
"Fierce clashes with all sorts of weapons are still ongoing Monday between the army and terrorist groups," LANA said, quoting a military source.
Loyalist forces have advanced into Hawari and control much of the district, it added.
The eastern city has been rocked by near-daily fighting for more than a year between pro-government forces and armed groups including fighters from the radical Ansar al-Sharia and IS.
LANA also cited an army spokesman as saying that a special forces commander, Imad el-Jazwi, was killed in a mine blast on Monday.
Jazwi had been searching a house in the central neighbourhood of Al-Laythi when the explosion killed him and wounded three members of his unit, the spokesman said.
Libya descended into chaos after the 2011 uprising that toppled and killed veteran dictator Moamer Kadhafi.
The North African nation has two rival parliaments and governments and several armed groups vying for power and its oil wealth.
The jihadist IS, which controls swathes of territory in Syria and Iraq, has taken advantage of the divisions to implant itself in Libya, seizing in June the coastal city of Sirte, Kadhafi's home town.
Libya Body Count, an independent website which collates data from different sources, says a year of fighting, air strikes and attacks has claimed more than 3,700 lives.
Most were killed in Benghazi, cradle of the 2011 uprising.