Israel killed a senior member of the Palestinian Fatah movement in Lebanon on Wednesday, accusing him of orchestrating attacks in the West Bank.

In response, the slain militant's Fatah party accused Israel of seeking to "ignite a regional war."

Khalil Maqdah was killed in a strike on his car in the southern Lebanese city of Sidon, according to Fatah and a Lebanese security source.

The Israeli military said an air force "aircraft struck the terrorist Khalil Hussein Khalil Al-Maqdah in the area of Sidon in southern Lebanon."

The military said Maqdah was the brother of Mounir Maqdah, who heads the Lebanese branch of Fatah's armed wing, the Al-Aqsa Martyrs' Brigades, and accused them both of "directing terror attacks and smuggling weapons" to the Israeli-occupied West Bank.

It alleged that the pair "collaborate on behalf of" Iran's Revolutionary Guards.

The attack marks the first such reported attack on a senior member of Fatah, the movement led by Palestinian president Mahmoud Abbas, in more than 10 months of cross-border clashes between Israel and Lebanon's Hezbollah movement following the Gaza war.

Fatah said Maqdah had been killed "in a cowardly assassination carried out by ... Zionist (Israeli) warplanes on Sidon," describing him as "one of the leaders" of the Al-Aqsa Martyrs' Brigades in Lebanon, the movement's armed wing.

In a statement, it said Maqdah had "a central role" in "supporting the Palestinian people and its resistance" during the Gaza war and an "important role in supporting resistance cells" for years in the West Bank. (AFP)