BBC Paris Correspondent Hugh Schofield writes:
The news is a breakthrough, because Abaaoud is regarded as an individual of great importance in so-called Islamic State - a man responsible for organising not just Friday's attacks, but also others such as the Thalys train attack two months ago. He is believed to have been a close friend of Salah Abdeslam, the eighth gunman who is still on the run. However identifying Abaaoud also raised serious questions. The man was high on French and Belgian wanted lists, and yet managed to travel from Syria to the heart of Paris without ever leaving a trace.