Army chief Gen. Khalifa Hifter is seeking to break months of stalemate and fully retake Benghazi. His offensive has primarily targeted the militant stronghold district of al-Laithi and government jets bombed multiple positions overnight and early Thursday morning, a military official said.
The bodies of six soldiers were brought to the Benghazi Medical Center, hospital spokesman Khalifa Gwaider said. A second army official, speaking on condition of anonymity because he was not authorized to speak to the press, said 13 bodies were brought to other area hospitals.
In a short statement posted on social networking sites, an Islamic State affiliate in Libya claimed responsibility for the attack.
A day earlier, IS also claimed responsibility for a second suicide bombing near the central city of Sirte one of the group's strongholds in which a bomber detonated his device at a checkpoint near the town of Hawara, killing one soldier.
The country split is between an elected parliament and weak government, which were forced to relocate from Tripoli to the far eastern cities of Tobruk and Bayda, and a rival government and parliament in Tripoli set up by the Islamist-linked militias that control the capital.
The turmoil has enabled the rise of an active Islamic State branch, which now controls at least two cities along the country's coastline.