The Israeli army says Lt Goldin went missing in an attack in southern Gaza on Friday morning
Israeli forces are searching for a soldier believed captured, as a 72-hour truce with Hamas in Gaza collapsed just hours after it had begun.
The soldier, named as Hadar Goldin, 23, disappeared when Israeli forces trying to destroy a suspected militant tunnel were attacked, Israel’s military said.
Two soldiers died in the firefight in the southern Gaza Strip at 06:30 GMT.
The Gaza health ministry said at least 53 people were killed by Israeli shelling shortly after the incident.
Hamas has not confirmed or denied capturing a soldier.
In 2006 Palestinian militants captured Israeli soldier Gilad Shalit and held him for five years.
He was released in November 2011 in exchange for 1,000 Palestinian prisoners.
Jon Donnison reports from Gaza, where a woman gave birth to quadruplets on the eve of a 72-hour ceasefire, which has since broken down
Lt Goldin’s father Simha said in a statement that the family was “confident that Israel will do everything to bring Hadar back home”.
US President Barack Obama called for the militants to free the soldier.
He said he “unequivocally” condemned Hamas for capturing the soldier “minutes after a ceasefire had been announced”.
President Obama: “That soldier needs to be unconditionally released”
Some 1,500 Palestinians, mostly civilians, have now died in the latest conflict, and 8,400 have been injured, according to Gaza’s health ministry.
Sixty-one Israeli soldiers have died, as well as three civilians in Israel.
Friday’s violence comes after a ceasefire brokered by the US and UN to give civilians a reprieve from the violence collapsed.
During the morning many Palestinians headed towards areas that had been heavily shelled areas to see if their homes were still intact.
But fighting then resumed, with Israel and Hamas accusing the other of breaking the ceasefire.
Fatah spokesman Dr Husam Zomlot: “I see entire families being wiped out”
Israeli government spokesman Mark Regev said the capture of the Israeli soldier could lead to ”escalation” in the conflict
Gaza’s health ministry said 53 Palestinians were killed and more than 200 injured in an Israeli attack near the southern town of Rafah after the ceasefire began.
Israeli foreign affairs spokesman Yigal Palmor told the BBC that Israeli forces had retaliated after being attacked in what seemed like a planned move by Hamas.
“There was a full-scale attack on an Israeli unit and this unit had to respond,” he said.
Israel says its response will be “crushing”.
But Hamas spokesman Fawzi Barhoun said: “The Israelis are the ones who breached the ceasefire, and the Palestinian resistance acted in a way that ensures its right of self-defence.”
Another Hamas official said the announcement of the soldier’s capture was “a justification for Israel retreating from the truth and a cover-up for massacres”.
Gazans were on the move once again on Friday, here fleeing Rafah as fierce fighting broke out
Analysis: Martin Patience, BBC News, Gaza
The clashes in Rafah came just four hours into what was meant be a 72-hour ceasefire, reinforcing just how difficult it is to get truces to last beyond a very short time. Both sides will have expected such violations.
While it held, much of Gaza was relatively quiet compared to the violence in recent weeks. The streets were slowly returning back to life as shops began to reopen. People had been taking the opportunity to stock up on much-needed supplies.
A steady stream of cars headed towards evacuated neighbourhoods close to the Israeli border. People here want to see if their houses are still standing and to try to salvage what’s left of their belongings.
Analysis: Bethany Bell, BBC News, Jerusalem
The news that an Israeli soldier appears to have been capt