AL FAWAR REFUGEE CAMP, West Bank (AP) _ Majdi Abu Wardeh disappeared last week, leaving behind his photograph with the words ``Farewell, Izzedine al Qassam Brigades'' _ the military wing of the militant Palestinian group Hamas _ written on the back.

Abu Wardeh and another missing Palestinian became suspects Tuesday in two weekend suicide bombings that killed 27 people in Jerusalem and Ashkelon.

Israeli soldiers raided their homes in the Al Fawar refugee camp outside Hebron late Monday, seizing documents and photographs. Troops arrested a dozen family members.

Palestinian officials said Israel was partially responsible for failing to prevent the attacks, noting the Hebron area is still under Israeli control.

Still, bowing to Israeli pressure, Yasser Arafat's security forces arrested more than 120 Hamas activists in the West Bank and Gaza Strip, Hamas members said. None of those detained belonged to Hamas' military wing, and only two were leading figures.

Arafat has ordered such arrest sweeps in the past after suicide bombings, but has always released the detainees later.

Israeli Prime Minister Shimon Peres has told Arafat he must disarm the group and arrest its leaders if he wants to remain a credible peace partner.

Peres said Tuesday that if Arafat did not keep his commitment to fight terrorism, Israel might delay its troop redeployment in Hebron, which is scheduled for late March.

``We expect Arafat to fulfill his part,'' Peres said. ``If not, we shall consider many things, maybe Hebron included.''

Palestinian officials tentatively identified the two suicide bombers Tuesday as Abu Wardeh, 19, and Ibrahim Sarahneh, 26.

They both left home Friday and have not been seen since, their families said. Sarahneh's mother, Maryam, said her son told her he was going on a trip with his friends and to ``look after yourself.''

Israeli authorities asked Mrs. Sarahneh and Mrs. Abu Wardeh to give blood samples, apparently to establish some match with the badly disfigured bodies of the bombers.

Israeli reports said both bombers were disguised in Israeli army uniforms, wearing earrings and carrying their bombs in olive green army bags so as not to arouse suspicion.

Palestinian Cabinet Secretary Tayeb Abdel Rahim said Israel shared responsibility for failing to prevent the attacks, because Israeli security officials had not given their Palestinian counterparts all the warnings they had received about planned suicide attacks.

He told Israel radio that Arafat would pursue Hamas' military wing, but would try to persuade the rest of the group to turn itself into a political party.

In a meeting Tuesday night with Arafat, Israel's armed forces chief of staff, Amnon Shahak, was to demand the immediate destruction of the hard core of Hamas. Shahak took with him a list of Hamas leaders Israel wants arrested.

Israel radio said Shahak was to tell Arafat that Israel's closure of the West Bank and Gaza Strip would stay in effect for the foreseeable future.

The closure, imposed immediately after Sunday's bombings, keeps 60,000 Palestinians from jobs in Israel and costs the Palestinian economy $4 million a day in lost wages and exports.

Shahak told a parliament defense committee Tuesday that Hamas is creating a secret group that would continue to carry out attacks even if Hamas reached an agreement with Arafat.

The bombings had been claimed by a previously unknown group, ``The Disciples of Yehiya Ayyash.'' Ayyash, a notorious bomb maker assassinated in January, was a member of Izzedine al Qassam. It was widely assumed that the ``disciples'' were mainly members of Izzedine al Qassam, the Hamas military wing, using a different name.

In a sign of apparent divisions in Hamas, Izzedine al Qassam said in a leaflet distributed Tuesday in the Gaza Strip that it was not responsible for the suicide bombings. It demanded that Arafat stop the arrests.

Israeli reports said the bombings apparently were masterminded by Mohammed Deif, 34, one of the commanders of Izzedine al Qassam.