About 1,000 university students and holders of foreign residency permits were eligible to cross, and by mid-afternoon Sunday, about 600 people had made the trip, border officials said.
Also Sunday, the bodies of four people were found in a smuggling tunnel under the Gaza-Egypt border, a day after another body was discovered in the area. Medics said all five suffocated.
The 20-month closure of Gaza by Israel and Egypt has boosted smuggling of arms and consumer goods through hundreds of border tunnels. Israel destroyed dozens of tunnels during its three-week offensive against Gaza's Hamas rulers last month, but smuggling continues.
The fate of Gaza's borders is key in two sets of Egyptian-brokered talks - on a truce deal between Israel and Hamas, and on a power-sharing agreement between Hamas and its rivals from President Mahmoud Abbas' Fatah movement. Hamas ousted Abbas' forces in a violent takeover of Gaza in June 2007.
Power-sharing talks between Hamas and Fatah are to begin Wednesday in Cairo, said Azzam al-Ahmed, a Fatah official in the West Bank. Hamas officials reiterated Sunday that Fatah must first release hundreds of Hamas prisoners, but it's not clear if Hamas would walk away from the talks if its demands were not met.
Efforts to form a unity government have failed in the past. However, after Israel's Gaza offensive, both sides have stronger motives to try to make it work.
Hamas needs a unity deal to end the blockade of Gaza and be considered a partner by the international community in rebuilding the territory. International donor countries are meeting in Egypt on March 2 for a pledging conference, to raise money for Gaza's reconstruction. Hamas will remain sidelined, including in reconstruction efforts, unless it moderates and allows Abbas a foothold in Gaza.
Abbas, meanwhile, has overstayed his term as president and needs a partnership with Hamas to shore up his dwindling political legitimacy. Abbas was elected to a four-year term which expired in January 2009, and pollsters say most Palestinians don't accept his claim that he could extend by a year.
In other developments Sunday, the Israeli military confirmed that an army dog bit an elderly Palestinian during an arrest raid in the West Bank village of Tamoun. The army said in a statement that soldiers, along with the dog, searched the house. The statement did not explain the circumstances of the attack.
Salem Bani Odeh, 99, has said he was in his bed when he was bitten repeatedly during the pre-dawn raid Friday. He remained hospitalized Sunday with a gash in his left ear.
Israeli troops regularly use dogs to detect explosives and search for militants.
Arab League In Gaza To Check Alleged War Crimes
An Arab League delegation is in Gaza to document alleged Israeli war crimes committed during its three-week offensive in the territory.
Sunday's delegation is made up of international legal and forensic experts. They will present their findings to the Arab League's chief, Amr Moussa. The Arab League, and its 22 member states, could then attempt to pursue war crimes charges in countries that allow such lawsuits to be presented.
Critics accuse Israel of using disproportionate force and failing to protect civilians during its three-week offensive, which ended Jan. 18. Israel launched its assault to halt years of Gaza militant rocket fire toward southern Israel.
Representatives of Gaza's ruling Hamas movement welcomed the delegation at the Rafah border crossing.