An apparent breakaway faction of a militia linked to Yasser Arafat's Fatah movement claimed responsibility for the bombing in the town of Kfar Saba near the West Bank. Witnesses said the bomber detonated an explosives belt as he was being checked by a security guard at the entrance to the station.
The attack underscored the difficulties the Palestinian prime minister-designate, Mahmoud Abbas, will face in subduing militias - a key requirement in a U.S.-backed "road map" to full Palestinian statehood within three years.
White House officials affirmed Wednesday that once the Palestinian parliament has approved Abbas' Cabinet - a vote is expected within a week - the United States will formally present the plan.
The blueprint, drafted late last year by the United States, the European Union, Russia and the United Nations, calls for an end to Palestinian attacks and a Jewish settlement freeze in the West Bank and Gaza.
Those actions could be followed as early as this year, by the creation of a Palestinian state with provisional borders. Final borders, the status of Jerusalem and the fate of Palestinian refugees are to be decided in later stages.
The presentation of the plan was in question for days, as Abbas and Arafat faced off over the formation of the Cabinet, particularly Abbas' choice of former Gaza strongman Mohammed Dahlan for a key security post. Dahlan has said he will not hesitate to crack down on Palestinian militant groups.
On Wednesday, following intense Egyptian mediation, Arafat withdrew his opposition to Dahlan, in exchange for assurances that he would be consulted on major security decisions, which would presumably include the disarming of militias.
Arafat backed down in exchange for guarantees regarding his personal safety and was told Egypt would ask Israel to lift a travel ban on him, in effect since December 2001. Several Israeli Cabinet ministers have called for Arafat's expulsion from the West Bank, an idea opposed by Washington.
The wrangling was a sign of Arafat's continued resistance to sharing power after four decades as Palestinian leader. The crisis also suggested Arafat would try in the future to limit Abbas' authority, while the new premier can count on international backing in such confrontations.
The United States and Israel have boycotted Arafat, accusing him of links to terrorism. They view the formation of a new Cabinet under Abbas as a major step toward sidelining the Palestinian leader.
Israeli officials said Thursday's suicide bombing underscored that there can be no progress toward a peace deal as long as such attacks continue. It should be the top priority of Abbas to "put an end to terror because terror and violence cannot go hand in hand with negotiations," said Foreign Ministry spokesman Jonathan Peled.
The blast went off at about 7:15 a.m. (0415 gmt) at a new commuter train station in the central town of Kfar Saba, north of Tel Aviv, and just several hundred meters from the Palestinian town of Qalqiliya in the West Bank.
A traveler said he saw the bomber being stopped by a security guard at the entrance to the station. "I ... saw him (the bomber) put his hand in his pocket," the witness, who only gave his first name, Rotem, told Israel Radio. "As I turned toward the guards ... there was an explosion."
Rotem said the guard was killed on the spot and that a female soldier standing nearby was hit by flying nails. The bomber was also killed.
Ten travelers were wounded, including one seriously, paramedics said.
The explosion tore light fixtures and wires from the overhang above the entrance. Blood, glass and scraps of flesh were scattered across the sidewalk and front steps.
In a call to The Associated Press, a man identifying himself as a member of the Al Aqsa Martyrs' Brigade, a militia linked to Fatah, claimed responsibility. The caller identified the bomber as 18-year-old Ahmed Khatib from the Balata refugee camp near the West Bank city of Nablus.
However, the official spokesman of the Al Aqsa militia, known by his nom de guerre, Abu Mujahed, said his group had nothing to do with the bombing. Abu Mujahed said the attack apparently was carried out by a splinter group of Al Aqsa. The militia consists of dozens of bands of gunmen who often act independently.
Khatib, who lived with an aunt in Qalqiliya, just a mile east of Kfar Saba, has been missing since Wednesday, his family said. An uncle said Khatib was a supporter of the Al Aqsa militia.
Thursday's blast is the first suicide bombing since an Islamic Jihad bomber detonated himself outside a cafe in the coastal city of Netanya on March 30, wounding 30 people. At the time, Islamic Jihad called the bombing "Palestine's gift to the heroic people of Iraq."
By Jason Keyser