TRIPOLI, Oct. 31 (Xinhua) -- Unidentified aircraft on Monday carried out air strikes on militant sites in the eastern city of Derna, killing and injuring dozens of people, according to a local source.

"Reconnaissance planes carried out a massive flight at 8:00 p.m. local time (1800 GMT) for about half an hour, followed by a few minutes' calm, before four air raids were heard on the mountain areas Al-Fata'eh and Al-Thuhr Al-Ahmar. Military headquarters of the Shura Council of Derna were targeted, dozens killed and wounded," a source in the local council of Derna told Xinhua.

"The strikes also killed and injured a number of civilians, as these military headquarters are located close to residential neighborhoods. However, the biggest losses were suffered by the forces of the Council," the source added.

"The planes cannot be identified, especially as they operated at night," the source said, noting that the strikes were mostly concentrated on military sites.

The Libyan Air Force has not claimed responsibility for the strikes so far.

Since mid-2015, Libyan eastern-based army forces led by General Khalifa Haftar have been imposing a land and sea blockade on the city of Derna. Residents are not allowed to enter or leave, except in humanitarian and medical cases.

The coastal city of Derna, located some 250 km northwest of Benghazi, is the only city in eastern Libya outside the control of the Libyan armed forces.

The army is demanding the Shura Council of Derna, which the army considers loyal to al-Qaeda, hand over its weapons and leave the city. But the Council refuses to recognize the army.

The Shura Council of Derna was formed at the end of 2014, consisting of a number of extremist armed groups.