After Sheik Is Slain, Hamas Picks Fiery Figure as Its Leader in GazaJERUSALEM, March 23 — The Palestinian Islamic movement Hamas selected one of its most combative figures, Dr. Abdel Aziz Rantisi, as its leader in the Gaza Strip on Tuesday after Israel's killing of the group's founder, Sheik Ahmed Yassin.
Meanwhile, senior Israeli security officials said top Hamas leaders would remain targets as part of a continuing campaign against Palestinians linked to violence against Israel. "Everyone is in our sights; there is no immunity for anyone," said Tzachi Hanegbi, Israel's minister of internal security.
Dr. Rantisi, who speaks often to journalists, has been the most visible and fiery Hamas spokesman in recent years. He vowed that with him as leader of Hamas from its Gaza stronghold, the group would continue to push hard to carry out suicide bombings and other attacks.
"The Israelis will not know security," Dr. Rantisi told the crowd at a memorial service on Tuesday for Sheik Yassin. "We will fight them until the liberation of Palestine, the whole of Palestine."
And in remarks directed at the "military wing" of Hamas, he said: "The door is open for you to strike all places, all the time and using all means."
While a major figure in the movement, Dr. Rantisi, a pediatrician in his mid-50's, lacks the towering stature of Sheik Yassin, who established Hamas in 1987. The sheik was killed in an Israeli helicopter strike as he left a Gaza City mosque after Monday morning prayers.
In Washington, President Bush did not repeat statements by a State Department spokesman that the administration was "deeply troubled" by the killing of Sheik Yassin. Instead, he told reporters that he was "worried about terrorist groups targeting America." He added, "Whether it be a Hamas threat, or an Al Qaeda threat, we take them very seriously in this administration."
The Hamas leadership structure is fuzzy — Sheik Yassin held the title of spiritual leader — and the full extent of Dr. Rantisi's authority was not immediately clear. Khaled Mashaal, based in Syria, remains head of Hamas's political bureau, an important decision-making body, Hamas officials said. In an interview Tuesday night with the Arab satellite television network Al Jazeera, Dr. Rantisi said he would "obey" the political bureau.
In the past, there has been tension between Hamas leaders in the Palestinian territories and those in exile.
The killing of Sheik Yassin seemed, at least in the short term, likely to increase regional violence as Palestinian groups called for retaliatory attacks. Israeli aircraft carried out an attack Tuesday night just across the border in southern Lebanon against a group of Hezbollah militants assembling a missile launcher, the Israeli military said. Two militants were killed and one was wounded, The Associated Press reported from Beirut, citing a Lebanese security official.
Also, Israeli soldiers shot and killed an armed Palestinian who was crawling as he tried to approach the Jewish settlement at Morag, in the southern Gaza Strip.
[Keeping up pressure in Gaza, about 10 Israeli tanks backed by helicopter gunships rolled about 100 yards into Khan Yunis refugee camp early Wednesday, and bulldozers razed several homes overlooking a Jewish settlement, Reuters reported, citing witnesses.
[About 60 families fled their huts as the tanks laid down covering fire, witnesses said. There were no immediate reports of clashes with Palestinian gunmen, or casualties. "The army is clearing the area where terrorists could fire mortar bombs and antitank rockets toward army positions and settlements in the area," an Israeli military official said.]
In Hamas, a group defined by its extreme positions, Dr. Rantisi is known as the leader who makes the most vitriolic statements and opposes any compromise with Israel. When Hamas and other Palestinian factions declared a unilateral truce with Israel last summer, Dr. Rantisi was a vocal critic of the decision. The truce never fully took hold, and collapsed within a couple of months.
Dr. Rantisi no longer practices medicine, and in recent years has taught medical courses at the Islamic University, where many students support Hamas. He spent years imprisoned by Israel, and was sent into exile in Lebanon in 1992 along with several hundred other Hamas members. The Palestinian Authority, which he frequently criticizes, also jailed him for about two years in the late 1990's. Last June he suffered multiple wounds when his car was hit by a missile on a Gaza City street, but quickly recovered.
While Dr. Rantisi describes himself as a political figure, Israel says there is no distinction between the "political" and "military" wings of Hamas and that Dr. Rantisi is among those who have orchestrated the group's suicide bombing campaign even if they have not planned the details of attacks.
The death of Sheik Yassin brought a deluge of international criticism directed at Israel, and it also produced a measure of Palestinian political unity, at least temporarily.
The Fatah movement, which is more nationalist than religious, is headed by the Palestinian leader Yasir Arafat and Prime Minister Ahmed Qurei, and is the main rival of Hamas in Palestinian politics. But Fatah leaders have lavished praise on Sheik Yassin, and Mr. Qurei traveled from the West Bank to Gaza to attend the memorial service.
"It is such an ugly crime committed by this government of murderers; it is the Israeli government that assassinated this symbol of resistance," Mr. Qurei said. "We are witnessing today, here in his memorial, the unity of the Palestinian people."
Israel, meanwhile, said it would press its current offensive in Gaza, which began a week ago in response to a double suicide bombing in the Israeli city of Ashdod by the Palestinians that killed 10 Israelis.
"If we will continue, in a determined way, with our strikes against Hamas and other terror groups, with the means I outlined, including action against those leaders, we will bring more security to Israeli citizens," said Israel's defense minister, Shaul Mofaz.
Israeli security officials acknowledge that Sheik Yassin's killing has energized the Palestinian factions. But they say Hamas and the other groups were already going all-out to strike at Israel.
"The Palestinians and Hamas feel they have lost a father," said Aharon Zeevi-Farkash, the head of military intelligence. "But I think they have done their maximum to attack us until now, and will do their maximum to attack us from now on."