JERUSALEM — A group of sick children and their companions left the Gaza Strip on Thursday in the territory’s first medical evacuation since an Israeli offensive shuttered the Rafah crossing with Egypt last month.

       The effort was coordinated by Israel, Egypt, the United States and other international partners, the Israeli military said in a statement. It came after weeks of mounting pressure on Israel to allow vulnerable Palestinians to leave the enclave, where a months-long war has decimated the health-care system.