Hamas named Gaza Strip chief Yahya Sinwar as its new political leader on Tuesday after his predecessor Ismail Haniyeh's killing in Tehran last week sent regional tensions soaring.
The Israeli military and officials accuse Sinwar of being one of the masterminds of the October 7 attack on Israel, making him one of Israel's most wanted militants.
"The Islamic Resistance Movement Hamas announces the selection of leader Yahya Sinwar as the head of the movement's political bureau," a statement from the group said.
Minutes after the announcement, Hamas's armed wing, the Ezzedine Al-Qassam Brigades, said it fired a barrage of rockets from the Gaza Strip towards Israel.
Sinwar's appointment as the new chief of Hamas comes less than a week after Haniyeh was killed in Tehran.
Iran and Hamas have blamed Israel for his assassination. Israel has declined to comment on the killing.
A senior Hamas official told AFP that by choosing Sinwar, the group is sending "a strong message to the occupation (Israel) that Hamas continues its path of resistance".
The official added on condition of anonymity that "the assassination of Haniyeh, who believed in reaching a ceasefire agreement and a prisoner exchange deal, leads Hamas to choose a leader who manages the battle and resistance against the enemy".
Hamas's October 7 attack on Israel resulted in the death of 1,198 people, mostly civilians, according to an AFP tally based on official Israeli figures.
During the attack, militants also seized 251 people, 111 of whom are still held captive in Gaza, including 39 the military says are dead.
Israel's retaliatory military campaign in Gaza has so far killed at least 39,653 people, according to the health ministry in the Hamas-run territory, which does not provide details on civilian and militant deaths.
A member of Hamas's Shura Council decision-making body told AFP that Haniyeh's killing "will not stop the resistance, and the movement will remain strong and cohesive with Sinwar as its leader, managing the confrontation with the occupation".