Around 630 Palestinians left Gaza and entered the Egyptian Sinai through the Rafah crossing on Sunday after Cairo authorised a temporary reopening of the border, a Palestinian official said.
It was only the second time in two months that Egypt had opened the Rafah terminal.
On Saturday, an Egyptian official confirmed to AFP that the crossing would be open on Sunday and Monday.
All of those crossing were either seeking medical treatment or were holders of a permit to stay overseas, according to Maher Abu Sabha, director of border crossings in the Gaza Strip.
The southern Rafah crossing is Gaza's only gateway to the world not controlled by Israel.
An AFP correspondent at the scene said hundreds of people had gathered in front of the terminal.
"At around midday (1000 GMT), three buses carrying around 200 people left Gaza through the Rafah terminal and entered Egypt," Abu Sabha said.
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On Monday, Palestinians studying abroad would be permitted to enter Egypt, he said.
Meanwhile Egyptian state media reported that Cairo deported 52 Palestinians to Gaza through Rafah on Sunday.
MENA news agency, quoting an unnamed official at the border, said 30 of the deportees had been rounded up for living illegally in Egypt, while the others had tried to enter without a visa.
After investigating their cases the security services decided to send them back to Gaza, the official said.
Cairo closed the crossing on October 25, the day after a deadly suicide attack killed 30 soldiers in north Sinai.
The closure has prevented thousands of Gazans from accessing medical treatment or higher education in Egypt and beyond, and also prevented some 3,500 Palestinians from returning home, the UN Office for the Coordination of Humanitarian Affairs said.
On Saturday, 378 Gaza residents were finally able to return to the enclave through Rafah, a Palestinian statement said.
During the first six months of the year, when the crossing was closed for a total of 22 days, an average of 6,400 people crossed each month, the UN said.