JERUSALEM/GAZA -- The Israeli military said on Thursday its forces had begun ground operations in northern Gaza, while Hamas' armed wing claimed responsibility for rocket attacks on central Israel, including Tel Aviv, escalating hostilities as a weeks-long ceasefire collapses.

Israeli troops began what the military described as "ground activity" overnight in the Beit Lahia area of northern Gaza, near the coastal border. Images released by the military showed soldiers and armored vehicles advancing, though it did not specify the scale or duration of the operation.

The move follows a "targeted ground operation" launched Wednesday in central and southern Gaza aimed at establishing a "buffer zone" to separate northern and southern parts of the enclave, according to Israeli authorities.

Shortly after the military's announcement, air raid sirens sounded in central and southern Israel on Thursday. The Israel Defense Forces (IDF) said three rockets were fired from southern Gaza, with one intercepted and the others landing in open areas. Loud explosions were reported in Tel Aviv, though no casualties were immediately confirmed.

Hamas' Al-Qassam Brigades said it had launched a rocket barrage at Tel Aviv in retaliation for what it called Israel's "massacres against civilians."

Israel resumed strikes in Gaza on Tuesday after a ceasefire that began on Jan. 19 unraveled, with officials stating the renewed campaign targets Hamas militants.

Gaza health authorities reported over 470 Palestinian deaths since Tuesday. Mahmoud Basal, spokesperson for Gaza's Civil Defense, said on Thursday that at least 71 Palestinians had been killed in Israeli airstrikes on residential areas since dawn, accusing Israel of targeting civilians.