The eastern Libyan city of al-Qubbah has been rocked by a triple car bomb attack, which has left dozens dead.
Reports vary on casualties. Reuters cites security officials and medics as saying at least 40 have been killed and 70 injured. Meanwhile, the country's deputy speaker Aguila Saleh told Saudi-owned TV station Al-Arabiya that at least 30 had been killed.
Saleh — whose hometown is Al-Qubbah — told the station that the attack had targeted a petrol station and a security building.
No immediate claim of responsibility was made but Saleh said it may have been militants retaliating for Egyptian airstrikes on nearby Derna.
"We are announcing seven days of mourning for the victims of Qubbah, I think this operation was revenge for what happened in Derna," he told Al-Arabiyah.
Egypt coordinated with Libya's military to launch airstrikes on militants in Derna on Monday. The strikes were in retaliation for the ISIS-affiliated mass beheadings of 21 Egyptian Coptic Christians on Sunday.
Libya has been plunged into chaos following the fall of strongman leader Muammar Gaddafi four years ago.
The internationally recognized government headed by Prime Minister Abdullah al-Thinni is based across several cities in the east of the country. The capital Tripoli, in the west, is under the control of a rival government, forcing Thinni to flee to the east.