By Ayman al-Warfalli
BENGHAZI, Libya (Reuters) - Military forces loyal to Libya's eastern government said on Thursday they had carried out air strikes overnight against Islamist fighters in Derna after Islamic State militants retreated from positions close to the city.
Derna has been the site of a three-way conflict between the forces loyal to the eastern government, an Islamist grouping known as the Derna Mujahideen Shura Council and Islamic State militants.
Fighters from Islamic State had controlled the city until the Shura Council forces pushed them out last June. The military has attacked both groups.
Military spokesman Abdulkarim Sabra said the overnight air strikes had targeted Shura Council fighters in Derna's Sayeda Khadija neighbourhood and at Bishr prison. He made no comment on possible casualties.
Shura Council spokesman Hafed Addabaa said the prison had held Islamic State suspects and added that the strikes had not caused any casualties or damage.
The military and the Shura Council both claimed credit for Wednesday's withdrawal of Islamic State from positions in Derna's 'district 400' and al-Fatayeh to the south of the city.
"We attacked Daesh (Islamic State) in al-Fatayeh to recapture the area ... The attack was from all sides except the south, which is where they fled," said Addabaa.
Five Shura Council fighters and six civilians were killed by mines and booby traps after they entered al-Fatayeh, he said.
Sabra, the military spokesman, said Islamic State had retreated because of a year-long blockade by the army and shelling by troops of the militants' positions.
Soldiers posted videos of themselves in al-Fatayeh on Thursday, saying they had control of the area.
Islamic State has gained territory in Libya as two rival governments and a range of armed factions have battled to control the country since 2014. But it has faced resistance from other local armed groups on the ground.
Derna, which has a history of Islamist militancy, was an early bastion for Islamic State fighters returning from Iraq and Syria in 2014. Though they lost control of Derna last year, the group established a stronghold in the central coastal city of Sirte.
Last month, a U.N.-backed Libyan unity government arrived in the capital Tripoli and is trying to establish its authority over the large oil-producing nation.
But allies of eastern military commander Khalifa Haftar have prevented moves by Libya's eastern parliament towards recognising the new unity government.
The military loyal to the eastern government has been making advances on the ground in Benghazi, Libya's second largest city, which is on the coast about 250 km (155 miles) west of Derna.
On Thursday U.N. Libya envoy Martin Kobler appealed to warring parties in Benghazi to help the departure of civilians who are trapped in areas where there is fighting and who wish to leave.
The United Nations says a large number of civilians including Libyans and migrant workers are trapped in several districts in Benghazi, where they face shortages of food and medical supplies.
(Additional reporting by Ahmed Elumami in Tripoli; Writing by Aidan Lewis; Editing by Gareth Jones and Richard Balmforth)