Top Hamas military official Saleh al-Arouri killed in Beirut blast

An explosion in Beirut on Tuesday killed Saleh al-Arouri, a top official with the Palestinian militant group Hamas, and three others, officials with Hamas and the Lebanese group Hezbollah said.

Lebanon's state-run National News Agency said the blast killed six people and was carried out by an Israeli drone. Israeli officials declined to comment.

If Israel is behind the attack it could mark a major escalation in the Middle East conflict. Hezbollah leader Sayyed Hassan Nasrallah has vowed to retaliate against any Israeli targeting of Palestinian officials in Lebanon. Lebanon's Prime Minister Najib Mikati said many people were injured in the explosion, which he called "a crime" and said was meant "to drag Lebanon into a new phase of confrontation with Israel."