Southern Gaza is running dangerously low on essentials like food and medicine, after the flow of aid has come to a near-total stop — first closed off by Israel and then further restricted, officials say, by Egypt.

Israel closed the crossing between Egypt and the southern Gazan city of Rafah this week after it sent in tanks and took over the Gazan side of the border. It also temporarily shut down the other crucial southern crossing, known as Kerem Shalom, after a nearby Hamas attack killed four Israeli soldiers on Sunday.

Kerem Shalom has since been reopened and some fuel has gone into Gaza, but food and medicine have not been allowed across since last Sunday, according to the main U.N. agency that aids Gaza.

Egypt, where most of the aid to Gaza is collected and loaded, is resisting sending trucks toward Kerem Shalom, according to U.S. and Israeli officials. They believe that Egypt is trying to pressure Israel to pull back from its operation in Rafah. Egypt fears that the Rafah operation could push Palestinian refugees onto Egyptian soil — an outcome the country views as a national security threat.

A Western official said Israeli military activity near Kerem Shalom has also partly destroyed the roads, making passage extremely difficult for aid trucks. Israeli officials say that they are doing everything they can to get aid into Gaza.

In related news, the U.N. General Assembly overwhelmingly voted to support Palestinian statehood, a symbolic move that the U.S. opposed.