Under an Egyptian-brokered truce, Hamas is supposed to stop cross-border rocket fire by Palestinian groups in Gaza.
In exchange, Israel is to ease its year-long siege of the strip and halt military raids.
Since the six-month ceasefire went into effect on June 19, goods crossings into Gaza have been sporadically or partially opened, but none have been returned to the level of activity they saw over a year ago.
"Everybody's trying to find a chance to travel and get out of the this prison"
Medhat Abbas, Palestinian health ministry official
Gaza's three crossings are each used for specific goods tranfers: Nahal Oz for fuel and gas, Sufa for products like fruits, vegetables, and medicine, and Karni for raw construction materials, such as as cement.
Limited goods came through Sufa and Nahal Oz last Sunday, nothing has come through Karni for a week.
The Erez passenger crossing - used mainly by diplomats and journalists - has continued to open regularly, but with the exception of a few special permit holders, is inaccessible to ordinary Palestinians.
Under the Israeli blockade, medicine and other vital supplies have been hard to come by.
Medhat Abbas, from the Palestinian health ministry, told Al Jazeera that there were at least 750 serious medical cases inside Gaza that required either a patient to be transported out or medicine delivered into the territory.
Egypt opened the Rafah crossing on Tuesday for a two-day period to allow some of the more urgent cases to seek aid across the .
But Abbas said only 50 or so criticial patients were able to cross the border.
"The others are simply waiting on this sunny day to pass through to Egypt," he said.
"Everybody's trying to find a chance to travel and get out of the this prison ... students and others. But this is to the detriment to the patients.
Reporting from the Gaza side of the crossing, Al Jazeera's Ayman Mohyeldin, said the situation could only be described as chaotic.
"About 1,000 Palestinians have been waiting by the crossing to see if they can get into Egypt, but we have been told that only about 300 or so will be allowed to go through."
The Rafah crossing is the main gateway for Gaza's 1.4 million people to travel abroad.
|Rafah is the main gateway for Gaza's 1.4m residents to travel abroad [AFP]
It was sealed after Hamas seized total control of Gaza, forcing out security forces loyal to Mahmoud Abbas, the Palestinian president, a year ago.
The closure has prevented people from travelling for medical care, studies and family visits, but Al Jazeera's correspondent said that, should the truce between Israel and Hamas stabilise, Rafah may be included as an item in the agreement.
"There was no mention that Rafah was due to be included in the truce agreement between Hamas and Israel, but we understand that it was due to be up for discussion," Mohyeldin said.
"If conditions during the truce stablise, then Rafah is supposed to open for all Palestinians to travel freely to and from Egypt. At the moment, it's only for 48 hours, and most say it's a goodwill gesture by the Egyptians."
In January, Hamas blew up the border wall between Egypt and Gaza, allowing thousands of people to move in and out of Egypt for nearly two weeks before it was resealed.