The fragility of the truce between Israel and Hamas was laid bare on Saturday, after Israel accused Hamas of withholding a hostage, prompting a halt in the movement of Gazan civilians back to their homes in the north.

The warning came a day after Israel said its forces would remain in south Lebanon beyond a Sunday deadline for their departure.

The Israeli government says its military will not withdraw from Lebanon by Sunday’s deadline, in violation of a ceasefire agreement that ended months of conflict with Hezbollah. Israel was expected to withdraw all of its forces from southern Lebanon as part of the deal but the Israeli government said some its forces would remain in southern Lebanon,

Secretary of State Marco Rubio’s orders could force many groups working on global aid to stop their programs. And the White House has approved sending more 2,000-pound bombs to Israel.

The United States has frozen nearly all foreign aid. The directive from the new Secretary of State, Marco Rubio, includes only two exceptions. Ukraine is uncertain whether it will receive the already approved U.