Palestinians sit outside 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]

JERUSALEM - The Israeli military found the bodies of three missing teenagers just over two weeks after they were abducted in the West Bank _ a grim discovery that ended a frantic search that led to Israel's largest ground operation in the Palestinian territory in nearly a decade and drew Israeli threats of retaliation.

"Hamas is responsible and Hamas will pay,'' Prime Minister Benjamin Netanyahu vowed, referring to the Islamic militant group that Israel has accused of carrying out the kidnappings.

The teenagers "were kidnapped and murdered in cold blood by human animals,'' the Israeli leader said as he convened an emergency meeting of his Security Cabinet on Monday night.

The three-hour session ended after midnight without any decisions, and officials were expected to resume deliberations on Tuesday.

Early Tuesday, Israel carried out an especially intense series of airstrikes in Gaza, saying it had struck 34 targets across the Hamas-controlled territory. The military said the airstrikes were a response to a barrage of 18 rockets fired into Israel since late Sunday.

"The IDF will continue to act in order to restore the peaceful living to the civilians of the state of Israel. The Hamas terror organization and its extensions are solely responsible for any terror activities emanating from the Gaza Strip,'' said Lt. Col. Peter Lerner, a military spokesman.

There were no further details on the targets, but in recent weeks Israel has repeatedly targeted launch sites and weapons storage areas in similar attacks. There were no immediate reports of casualties.

The kidnapping episode has put Netanyahu in a difficult position. With a public enraged over the deaths, the Israeli leader has widespread support to strike Hamas. But after a two-week crackdown against the group, he could have a tough time finding new targets. He is also facing international calls for restraint.

Eyal Yifrah, 19, Gilad Shaar, 16, and Naftali Fraenkel, a 16-year-old with dual Israeli-American citizenship, disappeared June 12 while hitchhiking home from the Jewish seminaries where they were studying near the West Bank city of Hebron. Despite the dangers, hitchhiking is common among Israelis traveling in and out of Jewish settlements in the West Bank.

In an operation codenamed "Brother's Keeper,'' Israel dispatched thousands of troops across the West Bank in search of the youths, closed roads in the Hebron area and arrested some 400 Hamas operatives throughout the territory. The search ended Monday afternoon with the discovery of the bodies under a pile of rocks in a field north of Hebron.

Israel has identified two well-known Hamas operatives from Hebron as the primary suspects. The men, Marwan Qawasmeh and Amer Abu Aisheh, remain on the run, and military officials said the search for them would continue.

Israeli soldiers blew up a door of Abu Aisheh's home in Hebron early Tuesday, but did not destroy the rest of the house, said an Israeli military official, speaking on condition of anonymity due to protocol. He did not elaborate

The search for the teens became a national obsession. Israeli media delivered round-the-clock updates, top officials held daily televised briefings and Israelis held prayer vigils. The mothers of the three teens became public figures as they campaigned for their sons' return, at one point traveling to Geneva to address the UN Human Rights Council in Geneva.

News of their deaths prompted an outpouring of grief late Monday. Large crowds of supporters rushed to the homes of the families in the central Israeli towns of Nof Ayalon and Elad, and the West Bank settlement of Talmon, while supporters lit memorial candles and prayed.

Large crowds gathered in Tel Aviv's central Rabin Square, and at the West Bank junction where the youths were abducted, singing songs, praying and lighting candles shaped in the names of the youths or the Jewish Star of David.