GAZA CITY, Palestinian Territories - Israel declared an end to a three-day Gaza truce only hours after it began Friday, saying it fears one of its soldiers was captured, jeopardising world efforts for a durable ceasefire.
Intensive shelling killed dozens of people in southern Gaza hours into the short-lived truce, with Hamas accusing Israel of breaking the ceasefire and Israel saying it was responding to rocket fire.
The skies over Gaza had initially fallen silent after the humanitarian truce announced overnight by US Secretary of State John Kerry, the longest of several agreed since the conflict broke out on July 8.
Starting from 0500 GMT, it gave brief respite to people in the battered strip from fighting that has killed nearly 1,500 on the Palestinian side, mostly civilians, and 63 Israeli soldiers and three civilians on the other.
Within hours air raid sirens warning of rocket fire were heard on the Israeli side of the border, and heavy shelling was resumed in the southern Gaza city of Rafah, killing at least 35 people and wounding 100, medics said.
Shortly afterwards the Israeli army announced the ceasefire was over, saying it was searching for one of its soldiers feared to have been captured in the enclave.
"Our initial indications suggest a soldier has been abducted by terrorists in an incident where terrorists breached the ceasefire," army spokesman Peter Lerner said.
The humanitarian truce was over and Israeli forces were pressing their "activities on the ground," he said, before the military said two soldiers had been killed in the fighting and named the missing man as Second Lieutenant Hadar Goldin, 23.
The office of Israeli Prime Minister Benjamin Netanyahu accused Hamas and other Gaza militants of "flagrantly violating" the ceasefire.
Hamas hit back.
"It is the (Israeli) occupation which violated the ceasefire. The Palestinian resistance acted based on... the right to self defence," Hamas spokesman Fawzi Barhum said.
AFP correspondents said there appeared to be fierce fighting ongoing in the vicinity of Rafah, and medics had trouble retrieving the dead and wounded.
The army warned residents of the city to remain in their homes, saying in voice messages to mobile phones it was "pursuing terrorist elements in Rafah".
Kerry had said earlier that once the ceasefire was under way, Israeli and Palestinian representatives, including from Hamas, would begin talks in Cairo on a more durable truce.
The ceasefire was a joint US-UN initiative and was aimed at giving civilians "a much needed reprieve", the top US diplomat had said.
Prior to the ceasefire deadline, Israeli tank and air fire killed 14 Palestinians in Gaza, and the army said five of its soldiers died in mortar fire near the border with the Palestinian coastal enclave.
And only minutes before the truce took effect, Palestinians had continued to fire rockets into southern Israel, with five brought down by missile defences, army radio said.
The Israeli army said that "five soldiers were killed during operational activity along the border with the Gaza Strip when a mortar was fired at the forces." While the ceasefire had been accepted in the name of all militant groups by Hamas, the main power in Gaza, the Islamist movement stressed it was dependent on Israel reciprocating.
Both Hamas and Israel issued statements saying they accepted the 72-hour humanitarian truce.
Hamas allies Turkey and Qatar welcomed the ceasefire.
But in a speech published after the ceasefire broke down, Saudi King Abdullah hit out at the "inexcusable" world silence over Israel's "war crimes" in Gaza.