Clashes between Libyan National Army (LNA) units and Islamic State (ISIS) fighters occurred in the Harouj mountains on 12, 14 and 15 June. On 13 June, LNA forces claimed to have killed six ISIS members, while others retreated into the mountains. On 14 June, the LNA forces composed of the Khalid Bin Walid Brigade and the 10th Infantry Brigade claimed to have killed twelve ISIS members and destroyed six ‘technicals’ – jeeps with guns mounted on the back.

On 14 June, ISIS released an Amaq report claiming to have killed fifty LNA fighters as well as the destruction of multiple armoured vehicles over two days of clashes with the LNA at multiple locations including Fuqaha, Samnu, and Tmassah, west of the Harouj mountains. In separate statements, one issued on the same day, the other on 13 June, ISIS claimed to have killed 30 and 19 LNA fighters respectively. On 15 June, ISIS claimed responsibility for an improvised explosive (IED) attack targeting LNA forces near Tmassah.

On 11 June, security forces stopped two Sudanese migrants at the Algerian-Tunisian border on suspicion of being members of ISIS as they had travelled from Libya. This follows reports on 8 June that the Algerian army fired upon a suspected ISIS armed group as they approached the boarder.

On 17 June, LNA forces claimed they observed ISIS elements between Sirte and Saddada.