Complex sentence: There were unconfirmed reports of British special forces operating in the area at the same time, while members of "al-Dawla al-Islamiyya" headed south to Homs or left Syria soon afterwards.
Split into simpler sentences: There were unconfirmed reports of British special forces operating in the area at the same time. It is believed members of "al-Dawla al-Islamiyya" left Syria soon afterwards.