Israel is pressing deeper into Gaza with tanks and soldiers as its ground offensive expands in the densely populated Palestinian enclave. The Israeli military said Tuesday it was “striking in all parts of the Gaza Strip,” particularly on the north, despite warning residents to move south for shelter. Israeli forces have entered the outskirts of Gaza City, with the initial movements of the assault shrouded in secrecy. Israeli Prime Minister Benjamin Netanyahu has rejected growing calls for a cease-fire, responding to criticism of his leadership and his position on the 240 hostages taken by Hamas militants. “This is a time for war,” he said, maintaining that fighting Hamas in Gaza is the best way to free the hostages.