Abu Yousef al-Turki, a key al-Nusra Front leader, has been killed in Syrian airstrikes, the group said in a statement. In the statement, which initially was posted on Twitter, the group says al-Turki (i.e. “the Turk”) was killed in U.S.-led airstrikes Tuesday. The statement was accompanied with an alleged proof-of-death photo, CNN reported.

The U.S. started conducting airstrikes in Syria late Monday as part of President Barack Obama’s pledge to “degrade and destroy” the Islamic State, also known as ISIS. Other terrorist groups in the region, including al-Nusra Front -- a branch of al-Qaeda -- have also been targeted in the strikes. So far, at least 50 of the group’s fighters were killed overnight, Reuters reported. The Syrian Observatory for Human Rights said of the 50 killed, most were non-Syrians.