Complex sentence: While the authorities were quick to blame the Kurdistan Workers' Party (PKK), only upon further investigation in the afternoon, the Turkish authorities changed their initial assessment, now instead blaming the Islamic State of Iraq and the Levant (ISIL).
Split into simpler sentences: While the authorities were quick to blame the Kurdistan Workers' Party (PKK). Only upon further investigation in the afternoon, the Turkish authorities changed their initial assessment, now instead blaming the Islamic State of Iraq and the Levant (ISIL).