In a major blow to Hamas leadership, Israel Confirms Death of Hamas Chief Mohammad Sinwar in Precision Tunnel Strike. Israeli forces have confirmed the death of Mohammad Sinwar, one of the group’s most senior commanders and the younger brother of Yahya Sinwar, during a precision strike on May 13. The Israeli Defense Forces (IDF) released new details and a 3D simulation of the tunnel complex beneath the European Hospital in Khan Younis, southern Gaza, where the strike was carried out.