The Times of Israel reports: Four former Hamas members took part in the Islamic State’s attack in the Sinai Peninsula that killed at least 23 Egyptian soldiers, a top Israeli defense official said Saturday.

According to the Coordinator of Government Activities in the Territories (COGAT) Maj. Gen. Yoav Mordechai, the four were previously members of Hamas’s military wing, but had left the group to join terrorists in Sinai. He did not say where the information had come from.

Mordechai, in a Facebook post, said this fact showed that Hamas is not actually helping Egypt fight Sinai’s jihadists but rather “enabling the free passage of terrorist elements between Gaza and Sinai and vice versa.”