A Palestinian man inspects the family home of an alleged abductor after Israeli troops set off an explosion on the top floor in the West Bank City of Hebron July 1, 2014.[Photo/Agencies]

"All of Israel bows its head today,'' said President Shimon Peres.

Thousands of Israelis have died in wars and militant attacks over the years, and Israel has grappled with the kidnappings of soldiers by militant groups in the past. But the ages of the victims, and the fact that they were unarmed civilians, seemed to strike a raw nerve. Security officials have long feared that civilian hitchhikers in the West Bank could make easy targets.

Beyond identifying the suspected kidnappers, Israel has not publicly provided evidence proving the involvement of Hamas, which has praised the kidnappings but not claimed responsibility for them. It is also not clear whether the kidnappers received orders from higher-ups or acted on their own.

Still, Hamas frequently encourages its members to try to kidnap Israelis, believing hostages could be used to win the release of militants detained in Israeli prisons. Tensions had also been high since the shooting deaths in May of two Palestinian teens during a stone-throwing clash with Israeli security forces.

News of the Israeli teens' deaths generated condemnations from around the world. Pope Francis, who in May visited the region, shared in the families' "unspeakable pain,'' said the Vatican spokesman, the Rev. Federico Lombardi.

In Washington, President Barack Obama sent his "deepest and heartfelt condolences'' to the families. "As a father, I cannot imagine the indescribable pain that the parents of these teenage boys are experiencing,'' he said. Yet he urged "all parties'' to refrain from steps that could further destabilize the situation.

UN Secretary-General Ban Ki-moon issued a similar condemnation of the "heinous crime,'' but also urged the sides to "refrain from any actions that could further escalate this highly tense situation.''

Israel's options may be limited. After a two-week crackdown on Hamas in the West Bank, few major targets remain there. Hamas had already been weakened by seven years of pressure by Israel and the forces of Palestinian President Mahmoud Abbas, and Israeli troops seemed to find very little during the latest crackdown.

Israel could turn its attention toward the Hamas-controlled Gaza Strip. Israel has been battling a surge in rocket fire from Gaza and could step up the intensity of its reprisals.

It also might consider stronger political action. Netanyahu has urged Abbas to disband a unity government he recently formed with Hamas' backing. The Israeli leader will almost certainly step up the pressure on Abbas.

Israeli media have also said that Israel might consider deporting Hamas leaders in the West Bank to Gaza.

In Gaza, Hamas spokesman Sami Abu Zuhri warned Israel against any broad offensive. Gaza militants possess thousands of rockets, and would almost certainly unleash heavy barrages at Israel if Israel attacks.

"Netanyahu should know that threats don't scare Hamas, and if he wages a war on Gaza, the gates of hell will open on him,'' he said.

Abbas has condemned the kidnappings, and his forces coordinated closely with Israel during the search for the teens. But he has so far refused Israeli calls to terminate the unity government, which ended a seven-year rift with Hamas. He says his new Cabinet remains committed to his political program.

The Palestinian president scheduled a meeting of the Palestinian leadership on Tuesday to discuss the events, his spokesman Nabil Abu Rdeneh said.

Abdallah Abdallah, an adviser to Abbas, said the Palestinians regretted the loss of life.

"We want peace to be created in this part of the world so no mother or no family will be bereaved for the loss of their beloved ones, Palestinian or Israeli,'' he said.