Islamic Jihad top leader Mahmoud Majzoub and his brother Nidal were killed Friday by a car bomb in the town of Siodn in Lebanon.
Majzoub's car after blast (Photo: AFP)
It was not immediately clear who targeted the official Mahmoud Majzoub, known as Abu Hamze, and his brother Nidal - also an Islamic Jihad member - but an Israeli military source said he was not aware of any involvement by Israel.
Islamic Jihad is the main Palestinian faction to defy a 15-month old truce with Israel, which it is committed to destroying.
Security sources said the explosion went off when the men, who were in the same car, turned the ignition. The blast, near the Abu Bakr mosque in Sidon, appeared to have been caused by a bomb planted in the vehicle, they said.
"Mahmoud al-Majzoub was critically wounded. Authorities told now us he is out of danger. But there was another martyr who was killed," Islamic Jihad representative in Beirut Abu Imad al-Rifai told Al Jazeera television. However, Mahmoud later died of his wounds at the hospital.
Rifai said it was the second assassination attempt on Majzoub, and blamed Israel for the blast.
Deputy secretary-general of the group, Ziad Nahalllah, said that "the Zionist enemy stands to lose if the campaign goes beyond Palestine's borders. Our hand is long and it can reach its institutions all across the world."
Jihad has killed more than 30 people in suicide bombings inside Israel since the start of a cease-fire which has been observed by some other Palestinian militant groups, including one that left 11 people dead in Tel Aviv on April 17.
Israeli forces have repeatedly targeted Islamic Jihad in the Gaza Strip and occupied West Bank with deadly missile strikes and arrest raids, prompting calls for revenge from the group.
Ali Waked contributed to the report