Cairo — A suicide car bomb attack in the eastern city of Benghazi targeting Libyan troops killed 23 people and wounded dozens of others on Tuesday, a hospital official said.The official said the wounded were still arriving at the hospital in the aftermath of the bombing in the al-Qawarsha district on the outskirts of the city, Libya's second largest. For the past two years, fighting has been raging in Benghazi between forces under the command of Brig Gen Khalifa Hifter and Islamic militias.The official spoke on condition of anonymity because he was not authorised to speak to the press.A coalition of Islamist militias called the Shura Council of Benghazi Revolutionaries, which includes the al-Qaeda affiliate known as Ansar al-Shariah, claimed responsibility for the deadly attack in a statement posted on its Twitter account.The attack comes after the United States started an air campaign on Monday in the central city of Sirte, the last bastion of the Islamic State extremist group in Libya. The strikes followed a request made by the internationally-recognised government and presidency council in the capital, Tripoli. The two executive bodies were formed after the United Nations brokered a deal among Libya's rival factions.Libya has descended into chaos following the 2011 ouster and the killing of long-time dictator Moammar Gadhafi. Since 2014, the country has been divided between two governments and parliaments, and a loose set of militias and tribes. The UN-brokered government led by Fayez Serraj aimed at healing the rift, but a crucial vote of confidence has yet to be obtained from the parliament.The parliament in eastern Libya does not recognise the UN government, and many in the east are angry that Serraj's administration invited foreign military intervention without the eastern parliament's consent.The US airstrikes, which were authorised by President Barack Obama, are supporting the militias of Misrata, a city next to Sirte that is leading the anti ISIS-operation. Misrata forces have been battling ISIS since May in fierce fighting that has killed and injured hundreds of militiamen.