JERUSALEM, July 21 (JTA) — After months of trying to find ways to deter Palestinian terror attacks, some Israeli officials thought they had an answer. Perhaps potential terrorists would rethink their plans if they knew that their relatives and friends would be deported from their West Bank homes to the Gaza Strip, the officials suggested. The proposal came as Israeli and Palestinian officials resumed high-level contacts over the weekend — and as an Israeli train was targeted in what police said they were treating as a new Palestinian terror attack. Backed by some Israeli security officials and politicians, the proposal touched off protests from the international community, including the United States and United Nations. Israel’s attorney general, Elyakim Rubinstein, soon weighed in with a qualified rejection of the proposal. The plan amounts to collective punishment and is therefore illegal, Rubinstein said Sunday. He did, however, approve deportations on a case-by-case basis if it is proven that the proposed deportee aided the terrorist or was involved in terrorist activity. On Sunday after Rubinstein had issued the guidelines, Israeli Prime Minister Ariel Sharon’s spokesman, Ra’anan Gissin, said there would be no deportations if there was no clear proof that an individual was involved in terror activity. Israeli officials “knew from the beginning it was problematic,” Gissin said. “If you can’t do the move in a legal manner, then you can’t do it.” Hamas last week threatened “unique martyrdom operations” if deportations are carried out. Last Friday, the United States issued a harsh criticism of the proposed deportations. “We expect that Israel’s actions in its campaign against terror will be based on information related to an individual’s culpability and not on personal or family relationships,” State Department spokesman Richard Boucher said. “Punitive actions against innocent people will not solve Israel’s security issues.” A spokesman for U.N. Secretary-General Kofi Annan expressed similar sentiments. Egyptian President Hosni Mubarak, who has been recently involved in efforts to renew the Israeli-Palestinian dialogue, warned that the deportations would only increase hatred toward Israel. Echoing an outcry from Palestinian officials, the secretary-general of the Arab League, Amre Moussa, said the deportations would violate international law. In a related development, Israel security forces operating around the West Bank city of Nablus last Friday demolished the homes of two alleged terrorist leaders. Soldiers tore down the home of Hamas member Nasser Assida, who is believed to have been behind the July 16 ambush of a bus near the settlement of Immanuel in which nine people were killed. They also tore down the home of Ali Ajouri, who allegedly dispatched the two suicide bombers who killed three people in a July 17 attack in Tel Aviv. The Israeli army spokesman said in a statement that “the demolition of the terrorists’ houses and those of their dispatchers is designated to make the terrorists aware of the price of their actions, thus attempting to prevent additional terror attacks.” Security forces also rounded up 21 male relatives of suspected Palestinian terrorists and began preparations to deport them to Gaza. On Sunday, Gissin said each of the 21 was being investigated to see if any fit Rubinstein’s criteria for deportation. Officials from army intelligence and the Shin Bet domestic security service supported the policy before Rubinstein issued his opinion. Legal observers believe Rubinstein’s cautious approach was affected by the establishment on July 1 of the International Criminal Court in The Hague. Even before the deportation proposal was floated, Israeli officials feared the court would be used to target Israelis — particularly settlers and soldiers — for prosecution. In the political arena, views were mixed. Foreign Minister Shimon Peres told Israel Radio that he supports the deportation policy, but only in those cases where it was backed by the attorney general. Opposition leader Yossi Sarid of Meretz said he was worried that the steady pace of Palestinian terror attacks had “interfered with the government’s judgment.” Labor Party member Yossi Beilin, a former justice minister, said the policy of demolitions and deportations is immoral and would not stop the suicide attacks. On Sunday, Israel was targeted in what police said was another terrorist attack. In the attack, a bomb exploded beneath a commuter train in southern Israel, moderately wounding the engineer. The blast occurred shortly before eight a.m., as the southbound train was traveling between the towns of Rehovot and Yavneh. One passenger was treated for shock. Police said the bomb was set off by remote control. Despite the explosion, the train did not derail, and rail traffic resumed later Sunday. In a similar incident on June 30, four people were lightly wounded when a bomb exploded on train tracks in central Israel. Police believe the same terrorist cell may be behind both blasts, the Israeli daily Yediot Achronot reported. Sunday’s attack occurred hours after Israeli and Palestinian officials resumed talks. During several hours of discussions Saturday night, when Peres met with Palestinian Authority official Saeb Erekat, Peres proposed a troop withdrawal from some Palestinian areas in the West Bank. The withdrawals would test the ability of Palestinian security forces to prevent attacks on Israeli civilians, Peres told Israel Radio on Sunday. “We have no interest in staying in those places where the Palestinians can prove that they can take control,” Peres said.