The Israel Defense Forces said it is fighting “fierce and difficult battles” across Gaza, including in three Hamas “strongholds”: Khan Younis, the largest city in southern Gaza, and Shejaiya and Jabalya in the north. The IDF announced Monday that starting Tuesday, the Kerem Shalom Crossing would be opened to screen aid entering into Gaza, increasing the volume of aid amid warnings from humanitarian organizations that Gaza’s health system is near collapse.