An explosion in Beirut on Tuesday killed senior Hamas official Saleh Arouri and three other people, Hamas officials and those of the Lebanese Hezbollah group said.
Lebanon's National News Agency said the explosion, which killed four people, was caused by an Israeli drone. Israeli officials declined to comment on the incident.
If Israel is responsible for this attack, the incident could mark a major escalation of the conflict in the Middle East. Hezbollah leader Sayyed Hassan Nasrallah has vowed to retaliate against any Israeli attack on Palestinian officials in Lebanon.
Hamas official Bassem Naim confirmed to the Associated Press news agency that Mr. Arouri was killed in the explosion in Lebanon. A Hezbollah official, speaking on condition of anonymity, also said that Hamas official Saleh Arouri was killed in the attack.
Saleh Arouri, one of the founders of Hamas' military wing, has led the group's operations in the West Bank. Israeli Prime Minister Benjamin Netanyahu had threatened to kill him even before the start of the Hamas-Israeli war on October 7.
The explosion rocked the Musharafieh neighborhood in the southern part of the Lebanese capital, a stronghold of the militant group Hezbollah, which is an ally of Hamas. The blast caused a huge fire on Hadi Nasrallah Street south of Beirut.
The incident follows a period of more than two months of heavy exchanges of gunfire between Israeli troops and members of Hezbollah along Lebanon's southern border.
Since the conflict began on October 8, fighting has been concentrated a few kilometers from the border, but on several occasions Israel's air force struck Hezbollah targets deeper in Lebanon.
Earlier in the day, Hezbollah said its fighters carried out several attacks along the Lebanon-Israel border targeting Israeli military positions./VOA