JERUSALEM — Israel's prime minister threatened Tuesday to take even tougher action against Hamas following an intense wave of airstrikes in the Gaza Strip, as the country buried three Israeli teens it says were kidnapped and killed by the Islamic militant group.

In comments broadcast live on national television, Prime Minister Benjamin Netanyahu said his first goal is to find the killers of the three teens. "We will not rest until we reach the last of them," he said.

But a broader mission is to act against Hamas in its Gaza stronghold, the Israeli leader said as he convened an emergency meeting of his Security Cabinet to discuss a response to the deadly abductions.

"Hamas continues to support, even at this time, the kidnappings of our citizens and is directly responsible for firing rockets and mortars at our territory, including in recent hours," Netanyahu said.

"If there is a need, we will broaden the campaign as much as needed."

The three teenagers — Eyal Yifrah, 19, Gilad Shaar, 16, and Naftali Fraenkel, a 16-year-old with dual Israeli-American citizenship — disappeared on the night of June 12 as they were hitchhiking home from Jewish seminaries they attended in the West Bank.

The abductions sparked Israel's broadest ground operation in the West Bank in nearly a decade, with the military deploying thousands of troops in a frantic search for the youths. Accusing Hamas of being behind the abductions, it also launched a massive crackdown against the group's West Bank infrastructure.

The manhunt came to a grim end on Monday when searchers discovered the teens' bodies under a pile of rocks in a field near the city of Hebron, a few miles from where they disappeared.

The plight of the teens captured the nation's attention, and the discovery of their bodies prompted an outpouring of grief. An estimated 50,000 mourners attended Tuesday's funeral in the central Israeli city of Modiin, arriving in hundreds of buses organized for the occasion.

"This day has spontaneously turned into a national day of mourning," Netanyahu said in his eulogy as the three bodies, wrapped in blue-and-white Israeli flags and laid out on stretchers were laid to rest side-by-side.

Earlier, hundreds of people had headed to the teens' hometowns for separate memorial services.

"Rest in peace my child," said Fraenkel's mother, Rachelle, who became a well-known figure during the ordeal as she sought to draw attention to the teens' plight. "We will learn to sing without you. We will always hear your voice inside of us."

"I don't have a brother anymore," said Gilad Shaar's younger sister, Shirel.

Thousands of Israelis have died in wars and violence with the country's Arab neighbors over the years, but these killings struck a nerve, largely because of the young ages of the victims and the fact that they were unarmed civilians.

"Today, we are burying a child who could have been any one of ours and therefore he is one of ours — all of us," Finance Minister Yair Lapid said at the memorial for Shaar.

Israel has identified two Hamas operatives as the chief suspects in the kidnappings. But it has offered little public evidence against the men, who remain on the loose.

It also is unclear whether the suspects acted alone or at the instruction of Hamas leaders. Hamas has praised the kidnappings, but not said whether it ordered the mission.

Hamas has long encouraged its members to kidnap Israelis, believing hostages could be used to win the release of thousands of Palestinian militants held in Israeli prisons.

Israeli security officials are not sure whether the kidnappers set out to kill the teens, or did so in a bout of panic after one of them called police. The officials, speaking on condition of anonymity because they were not authorized to talk to the media, said they believe the youths were killed minutes after the phone call.

Israeli media on Tuesday published a recording of the emergency call.

"They kidnapped me," a voice, believed to be Shaar, can be heard saying. Another male voice is then heard, shouting, "head down!" Hotline workers initially dismissed the call as a hoax, delaying the rescue efforts for several hours, and several workers have been disciplined for the mishap.

Channel 10 TV said investigators found evidence of their deaths in the burnt-out car, including bullet cases, blood that belonged to the victims and remains of a shirt.

Police spokesman Micky Rosenfeld said searchers found the bodies after discovering a sandal and a pair of eyeglasses belonging to the teens over the weekend. The objects helped rescuers narrow their search and the bodies were uncovered on Monday, he said.

The crackdown in the West Bank has been accompanied by a spike in violence in Gaza. Israel unleashed a wave of airstrikes on Hamas targets overnight Tuesday in response to repeated rocket fire.

Later on the day, militants fired five more rockets, including two that landed in Israel, the army said. In all, 10 rockets were fired into Israel on Tuesday, it said. The barrage, which caused no damage or injuries, raised the likelihood of new Israeli reprisals.

Despite the tough rhetoric, Netanyahu could find himself with limited options. Hamas has already been greatly weakened by a seven-year crackdown by Israel and the rival forces of Palestinian President Mahmoud Abbas. Critics said the recent arrest sweeps had found very few high-value targets.

A broad operation in Gaza would trigger retaliation by militant groups armed with thousands of rockets. It is unclear whether Israel has the appetite for a new confrontation, especially at time of so much turmoil throughout the region. A civil war is raging in neighboring Syria, and Netanyahu has expressed concerns that unrest in Iraq could spill over into Jordan, a key Israeli ally and neighbor.

Israeli defense officials said Israel was prepared to do whatever was needed to restore quiet. "We will continue the necessary activity in every area, with all force and scope necessary," Lt. Gen. Benny Gantz, the country's military chief, said as he stood alongside Netanyahu.

While Israel's allies have condemned the deaths of the teens, there have also been calls from the U.S., European Union and United Nations to show restraint.

In Washington, White House spokesman Josh Earnest said the U.S. is still seeking details "about who precisely was responsible for this terrible, terroristic act."

But, he added, "there is also a responsibility that both sides have to exercise restraint, to prevent this one terrible act from leading to a much broader, much more destabilizing situation."

Those calls for restraint were echoed Tuesday by Egypt, which borders Gaza to the south.

Israel will likely step up pressure on Abbas to terminate the unity government he formed last week with Hamas' backing to end a seven-year rift with the group.