When the mother of one of the Thai hostages held in the Gaza Strip for over a year caught sight of her son on a Facebook livestream after his release Thursday, he had changed so much that she didn’t recognize him at first.

The five hostages were among the 31 Thai agricultural workers who were captured by Hamas from four farms close to the Gaza border. Earlier, 23 hostages were released and two, Sudthisak Rinthalak and Sonthaya Oakkharasri, were confirmed dead in May of last year.

Israeli officials says they are delaying the release of Palestinian prisoners until Hamas can assure them future hostages will be freed safely.