Why is the Rafah crossing that Israel has seized crucial to Gaza?

The Israeli military said it had taken control of the Palestinian side of Gaza's southern Rafah crossing which borders Egypt and which has been central for the delivery of aid and the exit of injured people in the Gaza war.

What could that mean for people in Gaza?

Throughout the seven-month conflict, Rafah, the only crossing not run by Israel, has been a lifeline to the outside world for Palestinians in Gaza, allowing the delivery of aid and the evacuation of patients from a collapsed healthcare system.

Humanitarian sources told Reuters the flow of aid through the crossing had been halted. The Palestinian-run Gaza Crossings Authority said this was a "death sentence" against the people of Gaza, particularly the ill and injured who have been able to leave the blockaded territory only through Rafah.

The only other crossing point in the south, the nearby Kerem Shalom crossing, through which most aid to Gaza has been delivered recently, was also closed after a Hamas rocket attack that killed four Israeli soldiers, the military said.

The UN's humanitarian office spokesperson Jens Laerke said this left the two main arteries for getting aid into Gaza "choked off", with stocks low inside Gaza.

Catastrophic hunger, especially in northern Gaza, would get much worse if supply lines were interrupted, the UN Agency for Palestinian Refugees UNRWA posted on X. The UN food chief has warned a "full-blown famine" had taken hold in the north of the enclave of 2.3 million people.

The World Health Organization has previously voiced concern that closure of the Egypt-Gaza crossing would have a big impact on the supply of medicines and access for medi cal personnel.

Why is this crossing so important?

Israel controls all sea and air access to Gaza and most of its land borders.

It tightened its existing restrictions into a total blockade after October 7.

With Israel's border crossings closed, Rafah became the only way that Palestinians in Gaza can leave the 360 sq km coastal strip and has been a focal point of efforts to deliver humanitarian aid, and allow out injured people and foreign passport holders.

Qatar mediated an agreement between Egypt, Israel and Hamas, in coordination with the United States, to allow limited evacuations.

The first group of injured evacuees left through Rafah about three weeks into the war on November 1, followed by the first foreign passport holders.

Until May 7, Israel did not directly control the crossing, but it monitored all activity in southern Gaza from Kerem Shalom military base, and other surveillance. This is Israeli forces' first return to the Rafah crossing since Israel's 2005 disengagement from Gaza.

What are the other aid routes?

After announcing the blockade, Israel has progressively opened more crossings, most recently Erez in the north on May 1, which had been closed since it was destroyed during October 7 attacks.

Reopening the Erez crossing had been one of the main pleas of international aid agencies to alleviate hunger which is believed to be most severe among civilians in the enclave's northern sector.

An Israeli official said on May 1 there was a target of 500 aid trucks a day entering Gaza.

The Kerem Shalom crossing, where Israel, Gaza and Egypt meet, reopened to traffic in December and since then more than 14,000 trucks carrying aid for Gaza have entered through this route - even more than have been processed through Rafah, according to UNRWA data.

That crossing was closed for security reasons after an attack claimed on May 5 by Hamas' armed wing that killed four Israeli soldiers. It would reopen once the security situation allows, the Israeli military said.

Limited quantities of aid have also reached Gaza by sea and by airdrop. US troops began construction of a maritime pier off the Gaza coast in April that aims to speed the flow of aid into the enclave when it becomes operational in May.

What has hindered aid getting through?

The head of UNRWA, Philippe Lazzarini, has accused Israel of denying the UN aid access in Gaza. On May 5, he said the agency had recorded 10 incidents involving shooting at convoys, arrests of UN staff and long delays at checkpoints in just the last two weeks.

However, COGAT, an Israeli Defense Ministry agency tasked with coordinating aid deliveries into Palestinian territories, said it continued to enhance its efforts to boost aid to Gaza.

Lazzarini also called on the Palestinian militant group Hamas and other armed groups to stop any attacks on humanitarian crossings, refrain from aid diversion and make sure assistance reaches all those in need.