The grim discovery of three missing teenagers just over two weeks after they were abducted in the West Bank has led to threats of retaliation by Israel.

“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.

• More arrests in search for missing teens
• Palestinian politician arrested

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

Early on 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 aftermath of the airstrikes on one suspect’s home. Photo: Getty

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.

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 on 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 say the search for them would continue.

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

“The Palestinian Authority must make every effort to apprehend those responsible for these crimes.”

Australian Foreign Minister Julie Bishop has urged both sides to refrain from any escalation of violence, saying it will only hinder the peace process between Israel and Palestine.

But she condemned the murder of innocent civilians, and expressed her condolences to the families of the teenagers.

“The Palestinian Authority must make every effort to apprehend those responsible for these crimes,” Ms Bishop said in a statement.

US State Department spokeswoman Jen Psaki in Washington called on Israel and the Palestinian Authority to continue security cooperation “despite the tragedy and the enormous pain on the ground.”

UN Secretary General Ban Ki-moon blamed the “heinous act” on “enemies of peace” and called on all sides to exercise restraint.

Pope Francis, who led peace prayers in early June at the Vatican with Israeli and Palestinian leaders, condemned the “despicable and unacceptable crime,” Vatican spokesman Father Federico Lombardi said.

Meanwhile Israeli troops shot dead a young Palestinian man during a raid on the Jenin refugee camp in the northern West Bank.

They named the dead youth as Yusuf Abu Zagher, 18, and said the incident appeared unrelated to abduction of the teenagers.