TEL AVIV, Israel -- Israeli Prime Minister Benjamin Netanyahu said Tuesday he has ordered the army to immediately carry out "powerful strikes" in Gaza, and Hamas responded by saying it would delay handing over the body of a hostage, putting new pressure on the tenuous U.S.-brokered ceasefire.

The order from Netanyahu came after an Israeli official said Hamas had fired on its forces in southern Gaza and after the Palestinian militant group handed over body parts on Monday that Israel said were the partial remains of a hostage recovered earlier in the war.

Netanyahu called the return of these body parts a "clear violation" of the ceasefire agreement, which requires Hamas to return the remaining hostages in Gaza as soon as possible.

In another sign of the fragility of the ceasefire, Israe

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