Multiple suicide car bombings struck an eastern Libyan town, killing at least 45 people on Friday not far from a main base of the Islamic State group’s Libyan offshoot. The group claimed responsibility for the attack, saying it came in retaliation for recent Egyptian airstrikes that avenged the beheading of 21 Christian hostages by Libyan Islamic State militants. The massive bombings rocked the town of Qubba, which is under control of the country’s internationally recognized government and about 30 kilometers (19 miles) from Darna — a stronghold of Libya’s Islamic State branch. In a statement posted on social networking sites, the group said two of the “Caliphate’s knights” carried out the bombings, targeting what they described as a Libyan army operations room.