Power struggle for Libya

Fighters from Misrata fire weapons at Islamic State militants near Sirte March 15, 2015. Islamic State has been exploiting the turmoil in Libya, where the internationally recognized government of Libyan Prime Minister Abdullah al-Thinni and the administration in Tripoli and their respective allies are fighting for power. REUTERS/Goran Tomasevic

Libya Dawn fighters celebrate as a Libya Dawn aircraft bombed Islamic State militant positions near Sirte March 17, 2015.REUTERS/Goran Tomasevic

A fighter from Misrata's Marsa Kateeba walks in front of an unexploded aircraft missile, which the fighters say was fired by forces loyal to General Khalifa Haftar, near town of Sidre March 8, 2015. Kateeba is the Arabic word for unit. REUTERS/Goran Tomasevic

A fighter from Misrata sits on top of a vehicle near Sirte, March 16, 2015. REUTERS/Goran Tomasevic

Libya Dawn fighters patrol during a search for Islamic State militant positions near Sirte March 17, 2015. The Libya Dawn armed group backs the self-declared government in the capital Tripoli. REUTERS/Goran Tomasevic

Libya Dawn fighters patrol during a search for Islamic State militant positions near Sirte March 17, 2015. REUTERS/Goran Tomasevic

Libya Dawn fighters search for Islamic State militant positions during a patrol near Sirte March 17, 2015. REUTERS/Goran Tomasevic

Libya Dawn fighters search for Islamic State militant positions during a patrol near Sirte March 17, 2015. REUTERS/Goran Tomasevic

A Libya Dawn fighter shoulders a rocket-propelled grenade (RPG) launcher at a checkpoint near Sirte March 17, 2015. REUTERS/Goran Tomasevic

Fighters from Misrata clean bullets as they prepare to fight Islamic State fighters, near Sirte March 16, 2015. REUTERS/Goran Tomasevic

Libya Dawn fighters search for Islamic State militants during a patrol near Sirte March 17, 2015. REUTERS/Goran Tomasevic

A Libya Dawn fighter holds a heavy machine-gun as he rides in a vehicle with other fighters near Sirte March 16, 2015. REUTERS/Goran Tomasevic

Libya Dawn fighters search for Islamic State militants during a patrol near Sirte March 17, 2015. REUTERS/Goran Tomasevic

Fighters from Misrata open a container of ammunition as they prepare to fight Islamic State fighters near Sirte March 16, 2015. Militants loyal to Islamic State, the group that controls much of Syria and Iraq, have been exploiting chaos in Libya where two governments allied to armed factions are vying for power four years after the overthrow of Muammar Gaddafi. REUTERS/Goran Tomasevic

Fighters from Misrata adjust a belt of ammunition as they prepare to fight Islamic State fighters, near Sirte March 16, 2015. REUTERS/Goran Tomasevic

A fighter from Misrata stands at a checkpoint near Sirte March 16, 2015. REUTERS/Goran Tomasevic

Fighters from Misrata move towards positions of Islamic State militants, near Sirte March 15, 2015. REUTERS/Goran Tomasevic

A fighter from Misrata sits on top of a vehicle near Sirte March 16, 2015. REUTERS/Goran Tomasevic

A fighter from Misrata carries a rocket-propelled grenade (RPG) near Sirte March 15, 2015. REUTERS/Goran Tomasevic

A fighter from Misrata wears a gas mask to protect his face from wind near Sirte March 16, 2015. REUTERS/Goran Tomasevic

A fighter from Misrata uses a cell phone near Sirte March 15, 2015. REUTERS/Goran Tomasevic

Fighters from Misrata stop a vehicle to check for weapons, near Sirte March 15, 2015. REUTERS/Goran Tomasevic

Fighters from Misrata move towards positions of Islamic State militants, near Sirte March 15, 2015. REUTERS/Goran Tomasevic

A fighter from Misrata shouts to his comrades as they move to fight Islamic State militants near Sirte March 15, 2015. Islamic State, which analysts say is splintered into smaller factions in Libya, has sought to exploit turmoil in the major oil producer where two rival governments and their respective allies fight for power. REUTERS/Goran Tomasevic

Fighters from Misrata's Marsa Kateeba rest at their positions near the town of Sidre March 8, 2015. Kateeba is the Arabic word for unit. REUTERS/Goran Tomasevic