Complex sentence: On 2 June 2017, defectors from the Northern Brigade's Commandos of Islam Brigade reportedly joined Tahrir al-Sham, although Captain Kuja, leader of the unit, stated that he is still part of the Northern Brigade.
Split into simpler sentences: On 2 June 2017, defectors from the Northern Brigade's Commandos of Islam Brigade joined Tahrir al-Sham. However, Capt. Kuja, leader of the unit, stated that he is still part of the Northern Brigade.