Israel will not withdraw from a strategic corridor in the Gaza Strip as called for by the ceasefire, an official said Thursday. Israel's refusal could spark a crisis with Hamas and key mediator Egypt at a sensitive moment for the fragile truce.

The official, speaking on condition of anonymity in line with regulations, said Israeli forces needed to remain in the so-called Philadelphi corridor, on the Gaza side of the border with Egypt, to prevent weapons smuggling.