Israel has said it has scientific evidence that Hadar Goldin, the soldier feared abducted by Hamas on Friday in an ambush that shattered a humanitarian ceasefire, was killed in action during the attack.

The announcement, by Israel's chief military rabbi, came just hours after the prime minister, Binyamin Netanyahu, indicated that Israel's military operation was coming to an end. On Sunday, a number of tanks and other vehicles were seen leaving Gaza and redeploying along the border.

In a statement, the Israel Defence Forces (IDF) said : "Yesterday (Saturday, August 2) at 23:25, a special committee led by the IDF chief rabbi announced the death of the IDF infantry officer of the Givati Brigade, Lieutenant Hadar Goldin, who was killed in battle in the Gaza Strip on Friday, August 1, 2014."

The Israeli authorities confirmed that Goldin, 23, was related to the defence minister, Moshe Ya'alon. His funeral is scheduled for 5.30pm local time on Sunday, suggesting that remains had been recovered.

The IDF said it struck more than a dozen targets in Gaza overnight, and Hamas and other militant groups launched rockets towards southern Israel.

Army personnel met the soldier's family at their home in Kfar Saba on Saturday night to inform them. Hundreds of people from around Israel gathered outside praying and showing their support.

Earlier, Netanyahu said that, once demolition of Hamas's tunnels into Israel was complete, the military would prepare for continuing action "according to our security needs and only according to our security needs". Officials interpreted that as meaning Israel would adopt an approach of "quiet in return for quiet".

Israel had rebuffed attempts to negotiate an end to the Gaza conflict amid signs that it was moving towards unilaterally declaring a halt to fighting without an agreement that would involve concessions to Hamas. Military and political sources said the goal of "neutralising" cross-border tunnels was on the verge of being achieved.

Although heavy fighting continued around the southern towns of Rafah and Khan Younis, Saturday's developments suggested Israel may have turned its back on a negotiated settlement to the 26-day conflict.

A Palestinian delegation, including Hamas representatives, was expected to arrive in the Egyptian capital on Saturday night for talks aimed at forging another truce. But an Israeli cabinet minister, Yuval Steinitz, said in a television interview that Israel would not be sending a team. "We are currently not sending any representative to Cairo," he said, saying Hamas had repeatedly violated ceasefire deals."That leads us to the conclusion that with this organisation there is no point in speaking about an agreement or a ceasefire because we have tried it too many times."

The IDF said four tunnels had been destroyed. A source told Haaretz that the mission could be complete within 48 hours and Israeli TV reported some troops being withdrawn from Gaza. Israel renewed its intensive bombardment of Gaza following Friday's breakdown of a ceasefire brokered by the US and the UN after just two hours. The breakdown came after the abduction of Goldin and the killing of two other soldiers. The IDF said it had hit more than 200 targets in 24 hours, including the Hamas-affiliated Islamic University in Gaza City.

Reports from Rafah, in the south of the Gaza Strip and close to where Goldin was thought to have been taken, indicated heavy civilian casualties from Israeli bombardment of the area as troops continued to clash with Hamas fighters. About 100 people were killed and hundreds more were injured after fighting resumed. On Saturday night, the death toll of Palestinians exceeded 1,650 and Israel confirmed that it had lost 64 soldiers and three civilians, its highest death toll since the 2006 Lebanon war. Israel's deputy foreign minister, Tzachi Hanegbi, said his government has evidence that almost half of Palestinians killed were combatants. Gazan human rights groups say at least 80% of the Palestinians killed have been civilians.

Hamas had denied it was holding Goldin captive. It said its militants and the Israeli soldier were presumed killed in a subsequent Israeli air strike.

Meanwhile, a row broke out between David Cameron and Ed Miliband on Saturday night after the Labour leader described the British prime minister's "silence" on Israel's incursion into Gaza as inexplicable. Miliband said Britain must take a "leading role" in pressuring both sides to end the violence, and described Israel's killing of hundreds of innocent Palestinians as unjustifiable.

He said: "David Cameron should be playing a leading role in these efforts to secure peace. He is right to say that Hamas is an appalling, terrorist organisation. Its wholly unjustified rocket attacks on Israeli citizens, as well as the building of tunnels for terrorist purposes, show the organisation's murderous intent and practice towards Israel and its citizens.

"But the prime minister is wrong not to have opposed Israel's incursion into Gaza. And his silence on the killing of hundreds of innocent Palestinian civilians caused by Israel's military action will be inexplicable to people.

He continued: "I am a supporter of Israel and I believe in Israel's right to self-defence. But its military actions in the past two weeks have been wrong and unjustifiable."

Downing Street responded with a statement accusing Miliband of "playing politics" over the war.

A No 10 spokesman said: "The PM has been clear that both sides in the Gaza conflict need to observe a ceasefire. We are shocked that Ed Miliband would seek to misrepresent that position and play politics with such a serious issue."