JERUSALEM. 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 southern Gaza Strip at 9:30 local time.

The Gaza health ministry said dozens were killed by Israeli shelling in the area shortly after the incident.

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.

Hamas has not confirmed or denied capturing a soldier. Some 1,460 Palestinians, mostly civilians, have died in the latest conflict and 63 Israelis, mostly soldiers.

The ceasefire had been brokered by the US and UN to give civilians a reprieve from the violence, and had been seen as an unforeseen breakthrough after days of diplomatic deadlock.

The White House blamed Hamas for the ceasefire’s breakdown, describing the militant group’s attack on the Israeli soldiers as "barbaric”.

"This is an outrageous action and we look to the rest of the world to join us in condemning it,” Deputy National Security Adviser Tony Blinken told MSNBC.

Also on Friday, Palestinian and Israeli delegations arrived in Cairo, Egypt, with the hope of negotiating a longer-term cessation of hostilities, but Egyptian officials said the talks had now been postponed. The BBC’s Bethany Bell, in Jerusalem, says there had been enormous international pressure for a 72-hour lull to allow people in Gaza to bury their dead and restock with food.

During the morning life appeared to be returning to some kind of normality in Gaza, with many Palestinians heading towards heavily shelled areas to see if their homes were still intact.