Hamas, Israeli forces clash after hundreds killed

People chant anti-Israel slogans while waving Palestinian flags during a rally celebrating the attacks that the militant Hamas group carried out against Israel, in Istanbul, Turkey, Saturday, Oct. 7, 2023. (AP Photo/Khalil Hamra)

JERUSALEM/GAZA/SDEROT (Reuters): Israeli forces clashed with Hamas on Sunday (Oct 8), 24 hours after a surprise attack in which nearly 500 people were killed in the deadliest day of violence for 50 years.

This could undermine U.S-backed efforts to forge regional security alignments that could threaten Palestinian aspirations for statehood and the ambitions of the group's main backer, Iran.