A car bomb at a checkpoint in the Libyan oil port of Ras Lanuf killed seven people and wounded 11 others on Thursday, Petroleum Facilities Guard spokesman Ali al Hassi reported.
Hassi said that the car had been waiting in queue at the checkpoint and exploded when it reached the front. The casualties included guards and civilians, he added.
No group or individual has immediately claimed responsibility for the bombing.
DAESH terrorist group attacked Ras Lanuf and the nearby oil port of Es Sider this week.
On early Thursday, at least 65 people were also killed and dozens injured when a truck bomb exploded at a police training centre in Zilten town of Libya.
The attack, the deadliest in years since the fall of autocrat Muammar Gaddafi in 2011, came in wake of a UN deal, signed in December, between rival factions in Libya.
Libya is currently split between two rival parliaments, the General National Assembly (GNC) based in Tripoli and the House of Representatives (HoR) based in the eastern city of Tobruk.
The two governments, recently signed a UN-brokered deal to establish an unity government, despite resistance in both parliaments. A unity government could help in the battle against DAESH terrorists and make the country more stable.
Lack of unity in the country paved the way for DAESH to take advantage of security vacuum and expand its presence to Libya, where they have taken over the city of Sirte and launched attacks on oilfields.