GAZA - An Italian journalist, three Palestinian bomb disposal experts and two other people were killed in Gaza on Wednesday when unexploded munitions blew up, medical officials and police said.

The explosion occurred in Beit Lahiya, a town in the northern Gaza Strip that had been the scene of fierce fighting between Israeli forces and Palestinian fighters during a month-long war.

A three-day ceasefire, in effect since Monday, has given Palestinians an opportunity to search for unexploded munitions. Gaza's police force said it was mourning the deaths of its three men: the head of the local bomb squad, his deputy and another officer, killed when an Israeli shell detonated.

Italy's foreign minister, Federica Mogherini, offered the government's condolences to the family of journalist Simone Camilli and said his death underlined the urgency of finding a lasting solution to conflict in the Middle East.

"Once again, a journalist pays the price for a war that has gone on for too long, and for the second time in a few months we weep for the death of someone who was courageously working as a reporter," Mogherini said in a statement.

The Associated Press said Camilli, a video journalist, had worked for the U.S. news agency since 2005.

Meanwhile, Egyptian mediators raced to bridge gaps between Palestinians and Israelis Wednesday as they struggled to secure a lasting Gaza truce ahead of the midnight expiry of a three-day ceasefire, an official said.

The indirect talks, held at the General Intelligence headquarters in Cairo, were expected to go down to the wire, the Palestinian official said. By the time the deadline passes, the two sides must have either agreed on a permanent ceasefire, accepted an extension or risk a resumption of more than a month of bloody fighting.

Egypt brokered the 72-hour truce which took effect at 00:01 on Monday (2101 GMT Sunday), and has urged the Israelis and Hamas, the de facto rulers of Gaza, to make every effort to reach a permanent ceasefire.

Mediators have proposed that talks on key Palestinian demands of a seaport and an airport in Gaza be delayed until a month after a permanent ceasefire takes effect, according to the Egyptian proposal contained in documents seen by AFP on Wednesday.

Negotiations on proposals for the handover of the bodies of two slain Israeli soldiers held by Palestinian fighters in exchange for the release of prisoners in Israeli jails would also be postponed, according to the document.

Under the proposal, the buffer zone along Gaza's border with Israel would be gradually reduced and guarded by Palestinian Authority president Mahmud Abbas's security teams.

The negotiations "are in a very sensitive stage and we hope to reach an agreement" before midnight (2100 GMT), said Palestinian delegation head Azzam al-Ahmed.

Hamas is understood to be demanding clear commitments to opening the ports in Gaza, even if they are to be established at a later date. The Palestinians, included Hamas, are also demanding an end to the eight-year blockade of Gaza. The document was vague on the blockade, saying the crossings would be opened according to agreements reached between the Palestinian Authority and Israel. Palestinian officials had said Israel proposed easing restrictions at two of the six border crossings it shares with the small coastal enclave.

The Palestinians, for their part, have rejected an Israeli demand for Hamas and other fighting groups in Gaza to disarm. Hamas's negotiating position has been strengthened by support from the moderate Abbas, whose aide Azzam al-Ahmed is heading the delegation.

Hamas signed a unity deal with Abbas's Palestinian Authority in April, ending a seven-year rift. "The Israeli delegation negotiates with us as a Palestinian delegation, but the (Hamas-PA) division is uppermost in their minds," Ahmed said. "We will defend the Palestinian people's rights as a priority," he added.

Nearly 2,000 Palestinians have been killed since Israel launched its Gaza offensive on July 8 to halt cross-border rocket fire. On the Israeli side, 67 people have been killed, mostly soldiers.