The Israeli army confirmed Monday evening that search teams found the bodies of three kidnapped Israeli teenagers, and Prime Minister Benjamin Netanyahu vowed that the Islamist militant group Hamas, which it accuses of the abductions, will pay a heavy price.

Speaking at the start of a meeting of his security cabinet following the grisly discovery, Netanyahu said, “Hamas is responsible, and Hamas will pay.” He said the three “were kidnapped and murdered in cold blood by wild beasts.” The teenagers were abducted June 12 as they made their way home from their religious school in the ­Israeli-occupied West Bank.

The security cabinet concluded its meeting without making a clear declaration. It plans to meet again Tuesday.

In the weeks since the abductions, the Israeli military has conducted one of the largest and most aggressive sweeps in the West Bank in a decade. The fallout has included house searches, raids, arrests and even deaths, igniting new frictions between Israelis and Palestinians, who just three months ago were in the midst of U.S-brokered peace negotiations.

Netanyahu has said that Hamas, the militant Islamist group that rules the Gaza Strip, is directly responsible for the kidnappings and killings, and he has criticized Palestinian Authority President Mahmoud Abbas’s recent move to form a transitional Palestinian unity government backed by Hamas. Israel and the United States consider Hamas a terrorist organization.

Both Hamas and Abbas’s Fatah party say they are not responsible for the teens’ fate, although the Fatah leader was quick to condemn the kidnapping. In Washington, President Obama urged Israelis and Palestinians to “refrain from steps that could further destabilize the situation.”

While few details were released on the exact fate of the three teens, security officials said the bodies of Naftali Fraenkel and Gilad Shaar, both 16, and Eyal Yifrach, 19, were found in an open area close to Hebron, in the West Bank, near where they disappeared. Fraenkel was a dual U.S.-Israeli citizen. The three will be laid to rest Tuesday.

Lt. Col. Peter Lerner, an Israeli army spokesman, said the bodies were discovered about 5 p.m. Monday by civilian volunteer searchers and special forces near the village of Halhul just north of Hebron.

“They were under a pile of rocks, in an open field,” Lerner said. He said the army could not yet specify how the victims were killed or how long their bodies had been hidden there.

Lerner also said it was too early to determine what Israel’s response would be, but by Monday night some officials were calling for decisive action.

“There can be no forgiveness for the killers of children and those who sent them,” Economy Minister Naftali Bennett said in a statement. “Now is the time to act.”

On Thursday, Israel released the names of two suspects it said carried out the kidnappings. Israel said that both men are known Hamas operatives and that both have been missing since the three Israeli youths disappeared.

On Sunday, Palestinians reported that the wife of one suspect, Marwan Kawasma, had been questioned by the Israeli military and that the father of the second suspect, Amer Abu Aysha, had been arrested.

Israeli forces used explosives early Tuesday to blow off a door and gain access to one of the suspect’s houses during raids of their homes. Neither suspect was located.

Israel’s Channel 2 News reported that the bodies were found on land belonging to Kawasma’s family.

Lerner, the Israeli army spokesman, said that some of the people arrested since the teens disappeared were involved in the kidnapping and killing of the youths but that the main suspects were still at large.

“We will continue our manhunt to find the two fugitives and bring them to justice,” he said.

In Ramallah, seat of the Palestinian Authority government, a senior official of the West Bank’s governing Fatah party called the kidnapping “an Israeli story from the beginning.”

“Not even one Palestinian faction claimed responsibility for the kidnapping, so why do all the Palestinian people have to suffer?” asked Ziad Abu Ein, a deputy minister for prisoner affairs. The Palestinian Authority controls only 10 percent of the West Bank.

In addition to the tension in the West Bank, the days since the abductions have been marked by a sharp escalation in violence between Israel and militant groups, including Hamas, in the Gaza Strip.

The Israeli military said in a statement Sunday that more than 50 rockets had been fired from Gaza into Israeli territory. In response, Israeli army jets have pounded targets in Gaza. One Hamas operative was confirmed dead Sunday.

Early Tuesday, Israel carried out an especially intense series of airstrikes in Gaza, saying it had struck 34 targets across the territory. There were no immediate reports of casualties.

In response to the increase in Israeli airstrikes, Hamas released its first official statement Monday, accusing Israel of escalating tensions.

“Netanyahu . . . should know that his threats do not scare Hamas. If he is willing to start a war in Gaza, then the gates of hell will be open to him,” the group said in a statement.

Shaul Bartal, a retired major who served in various military positions in the West Bank, said, “It is a very sad day for all in Israel.” He said it was likely that some Israelis might take matters into their own hands and carry out what are known here as “price tag,” or revenge, attacks on the Palestinian population.

As for a large-scale, official military operation, Bartal said that it was too early to tell what action Israel would take in response to the killings but that it is likely “there will be something.”

Branigin reported from Washington. Sufian Taha in the West Bank and Islam Abdul-Karim in Gaza contributed to this report.