Like thousands of other Palestinians in the Gaza Strip who do not have access to advanced medical care, Hani Hindi traveled across the border to Cairo for specialized treatment. Three months ago, Hindi said, he had been shot by Israeli soldiers in the southern Gaza town of Khan Younis while installing a rooftop satellite dish.

But when he tried to return home two weeks ago, Hindi said, he was stunned to find that Israel, which controls all access to Gaza with fences and military patrols, had closed the gates on July 17 and was letting no one in or out.

Hindi, 22, and his wife, Malina, who is eight months pregnant, have been stranded since then at the Rafah border crossing with about 2,500 other Palestinians who are unable to cross into Gaza but lack the money or travel papers necessary to return to Egypt.

Hundreds of men, women and children -- many of whom, like Hindi, are returning home after medical procedures not available in the Gaza Strip -- are crowded into the crossing's arrival and departure halls, according to aid groups and people inside reached by cellular telephone.

Temperatures soar above 100 during the day and drop into the 60s at night. Many people are sleeping on flattened cardboard boxes surrounded by mountains of luggage or in makeshift tents set up outside. Blankets, water and toilets are scarce, and there are no showers or cooking facilities. The Egyptian Red Crescent Society has set up a small clinic, and two ambulances stand at the ready.

Egyptian police refused to allow a Washington Post reporter to enter the border crossing on Sunday to observe conditions and talk to people stranded there. Six people inside were interviewed by phone; two others were interviewed through the large iron gates at the Egyptian entrance to the crossing.

"It's awful," said Maha Jundia, 35, an official with the Palestinian Foreign Ministry who arrived at the crossing more than two weeks ago after attending a government training course in China. Jundia does not have money for a hotel or to go to Cairo to wait out the impasse.

"We sleep here on the floor, children all over the place, sick people," she said in a telephone interview. "Some Palestinians and Egyptians who live in the area brought food and stuff, but it is not enough. They brought enough for hundreds, but we are thousands."

"There are hundreds of children," said Sigrid Bovsor, 37, a medical statistician at St. Georg Hospital in Hamburg, who was on her way to Gaza to visit her husband's family when the border was closed. "They play with everything -- stones, broken things, empty bottles, their shoes," she said in an interview at the gate Sunday before Egyptian police ordered her away. "It's really boring."

Lt. Yaniv Alon, a spokesman for the Israeli army's Gaza liaison office, said Israel closed the border "due to a security alert regarding an attempt to dig a tunnel under the crossing." Palestinian militants dug a 1,000-foot-long tunnel under an Israeli army post in the southern Gaza Strip earlier this summer and detonated what they said were 3,000 pounds of explosives, collapsing a concrete building, killing one Israeli soldier and injuring five others.

An Israeli military spokesman said Egyptian and Palestinian authorities were told in advance of plans to close the crossing "to prevent the gathering of people." He said the Israeli government had offered to allow Palestinians to cross into Israel 27 miles south at a new border crossing facility and then be transported back up to the Gaza Strip, but that the Palestinians had refused.

Palestinians said the Israeli offer was limited to about 200 people per day, which they said was inadequate given the number of people stranded at Rafah. Other Palestinians opposed the deal on principle, saying Palestinians should not be forced to transit through Israel and be subjected to aggressive security checks when Egypt and the Gaza Strip share a seven-mile border.

Physicians for Human Rights, one of several groups that appealed to Israel's high court last week to open the border, said in a statement that the southern crossing proposal was a "symbolic" solution that was "not truly an option."

The situation underscores Palestinian concerns about Israeli Prime Minister Ariel Sharon's proposal to withdraw Israeli troops and settlers from Gaza. Under the plan, Israel would continue to occupy a thin strip of land along the border between Egypt and Gaza, allowing Israel to seal off Gaza.

Jundia, the Palestinian Foreign Ministry official, charged that the people trapped inside the border crossing were being used by Israel as "a political tool to pressure the Palestinian Authority."

"This is truly collective punishment," she said. "They should release us from here and then negotiate."

"It's humiliating," said Sabah Hamas, 42, a Palestinian housewife from Jiddah, Saudi Arabia, who was accompanying her 22-year-old daughter, Hanna, to Gaza City for her wedding when the border was shut. "It's hot here, like being in a prison dungeon. We need a solution."

About 500 guests were invited to the wedding, which had been scheduled for Saturday but was canceled, said the groom, Dia El-Jidi, 24.

"Now there is no date until the passage is open," he said in a telephone interview Saturday. "I feel very disillusioned and disappointed. I'm losing hope. This has become the saddest day in my life."

An Egyptian who works at the crossing, who spoke on condition of anonymity because of concerns about his job, said about 2,000 Palestinians were living in local hotels and many were arriving at the crossing each day because of rumors that the border would open.

"Rafah is everything to Gaza: passengers, white flour, rice, oil, cement," he said. "Because it is the only entry, everything that's in Gaza must come from Egypt. And now Gaza is a jail."

Bovsor, the medical statistician from Hamburg, said she could leave but chose not to.

"This is a desert camp. It's rough out here. The toilets, the hygienic situation is poor. There are hundreds of people stuck here. Sometimes there is shortage of water," she said.

In the Khan Younis refugee camp in Gaza, Israeli troops opened fire Sunday, killing a 60-year-old woman and wounding four other Palestinians, Palestinian witnesses and medics told the Reuters news agency. The shooting occurred as Israeli tanks took up positions on the edges of the camp in what military sources said was an operation against "terrorist infrastructure." They did not elaborate.

In northern Gaza, Israeli soldiers opened fire on three Palestinian gunmen who approached a Jewish settlement, military sources told Reuters. It was not clear whether any of the gunmen were hit.

[An explosion ripped through a Palestinian prison in Gaza City on Monday, wounding several people, a Palestinian security source told the Reuters news agency. It was not immediately clear what caused the blast in the Palestinian security compound. Israeli military sources said Israel had nothing to do with the explosion.]

Special correspondent Samuel Sokol contributed to this report.

Hundreds of Palestinians are crowded in arrival and departure halls at the Rafah crossing on the border of Egypt and the Gaza Strip. Israel closed the crossing July 17.