The Israel Defense Forces said Friday morning that its ground troops had begun operating in the Shejaiya area of the northern Gaza Strip.

Israel’s military operation in the Gaza Strip is expanding to seize “large areas,” the defense minister said, while officials at hospitals inside the Palestinian territory said that Israeli strikes overnight and into Wednesday had killed more than 40 people,

Israel’s defense minister said the military is taking control of significant territory to establish security zones.

At least 73 people were killed during Israeli attacks in the Gaza Strip on Wednesday, according to the Hamas-controlled health authority, as Israel launched a major expansion of military operations. A recent ceasefire has become a distant memory for Palestinians in the coastal enclave after Israel announced plans to establish another security corridor dividing the strip and the army said it had encircled part of the southern Gazan city of Rafah.

Israel announced a major expansion of military operations in Gaza on Wednesday, saying large areas of the enclave would be seized and added to its security zones, accompanied by large-scale evacuations of the population.

Prime Minister Benjamin Netanyahu said Israel had seized a corridor of land that would split one of Gaza’s largest cities from the rest of the enclave.