Muhammad Sinwar, a Top Military Leader of Hamas, Is Dead, Israel SaysHe was the younger brother of Yahya Sinwar, the former Hamas leader killed by Israel last year. Hamas did not immediately respond to the claim of his death.
Source: Muhammad Sinwar, a Top Military Leader of Hamas, Is Dead, Israel Says (https://www.nytimes.com/2025/05/31/world/middleeast/muhammad-sinwar-hamas-israel.html)