5 Israelis killed in tunnel attack

JERUSALEM -- Palestinian militants yesterday detonated an explosives-packed tunnel under an Israeli army base in the Gaza Strip and ambushed Israeli reinforcements, killing five soldiers and complicating efforts underway since Palestinian leader Yasser Arafat's death last month to halt more than four years of fighting.

The explosion marked the deadliest attack on Israel since Arafat died Nov. 11 and demonstrated a level of sophistication not usually seen by the groups that claimed responsibility -- the Islamic Hamas and a Fatah offshoot.

In the West Bank town of Ramallah, meanwhile, Palestinians announced that imprisoned uprising leader Marwan Barghouthi was withdrawing from the race to succeed Arafat as president but demanding that Mahmoud Abbas, the election frontrunner, pledge not to end the uprising.

In Gaza, members of two Palestinian factions had burrowed for months under the base near the territory's border with Egypt and packed the tunnel with more than a ton of explosives, a process the militants videotaped.

The blast at about 6 p.m. in the town of Rafah collapsed several structures and trapped soldiers under rubble. Palestinian gunmen then sprayed the base with fire, wounding backup forces. At least one Palestinian gunman was killed in the ensuing firefight.

Captain Jacob Dallal, an Israeli army spokesman, said a building where travelers between Egypt and Gaza are processed was among the structures damaged and would be closed until further notice.

''This was a very large, well-coordinated, planned attack against an international crossing used by Palestinian civilians to cross into Egypt," Dallal said.

Witnesses said Israel amassed troops near Rafah hours after the attack, raising the possibility of a widespread counterassault. Israel has staged several forays into Gaza in the past year, including an extended incursion into Rafah six months ago to find and destroy underground tunnels used by Palestinians for smuggling weapons and explosives.

Early today, witnesses said, Israeli attack helicopters fired several missiles at a metal foundry and other targets in Gaza City, Reuters reported. There were no immediate reports of casualties.

Several Arab television stations showed a Palestinian militant who gave his name only as Abu Majad claiming responsibility for yesterday's attack on behalf of the Fatah Hawks, a group affiliated with Fatah, the main faction of the Palestine Liberation Organization.

He said the group was retaliating for Arafat's ''assassination" by Israel, a reference to rumors circulating widely in the Arab world, though not supported by medical evidence, that Israeli agents poisoned the Palestinian leader.

Abu Majad said the tunnel was more than 600 yards long.

The Islamic Hamas group released a video filmed during work on the tunnel showing militants, one with a lighted miner's hat, digging underground and pushing explosives along a narrow dirt warren.

Israel says Palestinians have smuggled tons of explosives and thousands of weapons through such tunnels from Egypt since the uprising began in September 2000. A senior Israeli security official, briefing reporters in Tel Aviv earlier this month, said Palestinians had even managed to smuggle in five antiaircraft missiles, though none have been used in the fighting.

The smuggling has been the focus of recent talks between Israel and Egypt ahead of Israel's planned withdrawal from Gaza this summer. Officials in Prime Minister Ariel Sharon's office have said Israel is ready to withdraw troops from the border area as well if Egypt can halt the gun-running.

Relations between the two countries have improved considerably in recent weeks.

Egypt is also trying to mediate a cease-fire between Israelis and Palestinians that would lead to a resumption of long-dormant peace talks. But Israel said yesterday after the attack that Palestinians had to begin collecting weapons from groups like Hamas.

''Unless there is decisive and sustained effort taken to dismantle the terrorist organizations, it will be impossible to move toward normalization and toward political negotiations," said Sharon's spokesman, Ra'anan Gissin.

The fate of the uprising has been one of the issues hotly debated in the run-up to the Palestinian presidential election Jan. 9. Abbas, Arafat's longtime deputy, has been trying to build support for stopping the intifadah, believing it has hurt the Palestinian cause.

Until yesterday, the 45-year-old Barghouthi was his main rival. A popular Fatah leader and member of the Palestinian Legislative Council, Barghouthi is serving five life terms in an Israeli prison for orchestrating intifadah-related attacks.

His withdrawal from the race follows a dramatic few weeks in which he kept dithering about whether to compete. After initially declaring that he would not run, in order to maintain Fatah unity, Barghouthi registered for the campaign at the deadline, saying he feared for the future of the uprising.

Polls had him running neck and neck with Abbas, who is the official candidate of Fatah.

In a letter from his prison cell in Beersheba, in southern Israel, Barghouthi said he would support the 69-year-old Abbas, calling him ''a dear brother" who ''is worthy to take the position of presidency."

But he included no fewer than 18 ''recommendations" for the Palestinian leadership that analysts said Abbas would have to take seriously if he wanted to maintain support from Fatah's younger leaders.

The letter was read out by one of Barghouthi's supporters at a Ramallah news conference yesterday organized by his wife, Fadwa.

Among the points that would be hard for Abbas to accept is the demand that no peace talks be conducted until Israel halts the expansion of settlements in the West Bank, removes checkpoints scattered across the West Bank and Gaza, and dismantles a barrier it is building to separate Israelis and Palestinians.

Barghouthi also called for the release of all prisoners before Palestinians sign any deal with Israel.

Barghouthi said the leadership should consider continuing the intifadah while negotiating with Israel.

With Barghouthi out of the race, Abbas is expected to win easily.

Seven other candidates are still running, but none has the following of Barghouthi, who helped found the Al Aqsa Martyrs' Brigades, a militant group affiliated with Fatah.

Globe Correspondent Sa'id Ghazali contributed to this story.