At least 15 Israeli soldiers have been killed in battles in northern Gaza since Tuesday as its forces press deeper into the enclave, attacking dozens of targets affiliated with its Hamas rulers, the Israeli military said.

The 15 deaths, mostly of infantry soldiers, were the first casualties inside the Gaza Strip publicly confirmed by Israel’s military since it launched a ground invasion Friday, as fighting appeared to intensify and its forces pushed closer to Gaza City, the biggest city in the territory.

The military wing of Hamas said on Tuesday on Telegram that its fighters had ambushed some Israeli soldiers at a building in Beit Hanoun in northern Gaza.

In Israel, a small country in which military conscription is a mandatory rite of passage for many Jewish citizens, the soldiers’ names and faces were plastered on the home pages of most news websites. Others were read out live on Israeli television when the military announced their death.