A founding member of Hamas was killed in a car bombing in the Syrian capital Damascus on Sunday in an attack blamed on Israel by the Palestinian movement which vowed to wreak a bloody revenge.
In Gaza, the armed wing of Hamas threatened to strike Israeli targets abroad to avenge the killing of Ezzedine Sheikh Khalil, but a politburo member in Beirut denied the leadership had decided to "take the fight out of Palestine."
Israel has threatened to strike Hamas members at home and abroad, including the Syrian capital where a number of the movement's senior officials are based, but officials in Jerusalem denied knowledge of the car bombing.
The attack came as Israeli Prime Minister Ariel Sharon presented his cabinet with the final draft of his controversial Gaza pullout plan and vowed to intensify action to stop Hamas firing makeshift rockets from the territory.
A senior source close to Sharon said he had "no information about this (Damascus) incident" other than through media reports, while the Israeli army also denied knowledge of the strike.
But Hamas said it was clear who was behind the killing of Khalil, one of the group's founders who was among 400 militants expelled by Israel to Lebanon in 1992 during the last intifada.
"This ugly Zionist crime targeting leaders outside shows Israel is trying to export the crisis and to drag the whole region into the inferno," said Mushir al-Masri, a spokesman for Hamas in Gaza.
And in a statement in Gaza, Hamas's armed wing, the Ezzedine al Qassam Brigades warned: "The Zionist enemy opened the door for the battle to move outside Palestine." But Mohamad Nazzal, a Hamas politburo member in Beiurt, denied that the movement's leadership had decided to strike Israeli interests abroad.
"Until today, the issue of carrying the fight outside Palestine is under study and no decision has been taken in that direction," he told AFP.
In the wake of the raid, Israel warned its campaign against Hamas would reach all the way to the movement's Syrian-based leadership.