The death toll from suicide bombings in a town in eastern Libya has increased to at least 45.

The deaths came in three suicide bombings in the town of Qubba. In the deadliest, an attacker driving an ambulance packed with explosives rammed into a fuel station where motorists were queuing, army spokesman Mohammed Hegazi said.

Two other bombers detonated vehicles next to the house of the parliament speaker and the security headquarters in Qubba, about 19 miles from Darna, a stronghold of Libya's Islamic State branch.

Two security officials say at least 45 people were killed. Government spokesman Mohammed Bazaza put the toll at 42 but said it is likely to increase.