Hamas acknowledged responsibility on Saturday for a deadly Gaza Strip ambush in which an Israeli army officer may have been captured, but said the incident likely preceded and therefore had not violated a U.S.- and U.N.-sponsored truce.

The statement by Hamas's armed wing, the Qassam Brigades, appeared aimed at preempting any intensification of Israel's 25-day-old offensive in the Palestinian enclave and deflecting international blame for the collapse of Friday's cease-fire.

But in a signal the war could wind down, Israel's military said its objectives, chiefly the destruction of tunnels dug by Hamas for cross-border attacks, were close to being achieved.

Israel says Hamas gunmen and a suicide bomber stormed out of a tunnel to ambush its infantrymen in southern Rafah at 9.30 a.m. on Friday, one and a half hours after the halt to hostilities came into effect, killing two troops and hauling another, Lt. Hadar Goldin, away through the underground passage.

The incident triggered Israeli shelling of Rafah from the mid-morning that killed 150 Palestinians. By early afternoon, Israel declared an end to the truce, which was meant to have lasted 72 hours, allowing humanitarian relief to reach Gaza's 1.8 million Palestinians and for further de-escalation talks.