At least 20 fighters were killed in clashes in eastern Libya between Islamic State and another Islamist force that later declared jihad against its hardline rival, residents and medical sources said on Wednesday.

Forces loyal to the official government later sent an air strike against suspected Islamic State positions in Derna, said Nasser al-Hassi, spokesman for Benghazi’s air base.

Fighting erupted in the city of Derna after a leader in the Islamist umbrella group Majlis al-Shura was killed, apparently for refusing to swear allegiance to Islamic State’s leader Abu Bakr al-Baghdadi, according to residents. […]