"There is no justification for the closure of the Rafah crossing," Hamad al-Raqb, a spokesman for the protesters, said in a speech marking the beginning of a four-day sit-in.
"It is unbecoming of the historic relations between Egyptians and Palestinians," he insisted.
Leading Hamas figures and MPs attended the launch ceremony.
Egyptian authorities have tightened their control over the border with the Hamas-run Gaza Strip since last July's ouster of elected president Mohamed Morsi by the Egyptian army.
In recent weeks, Egypt has repeatedly closed the Rafah crossing, which – due to an ongoing, eight-year Israeli siege – represents Gaza's only window to the outside world.
The Egyptian army has also launched a campaign aimed at destroying the network of tunnels linking Gaza to Egypt's Sinai Peninsula, which in recent years had been used to bring vital commodities into the besieged coastal enclave, home to nearly 2 million Palestinians.
Hamas, an ideological offshoot of the Muslim Brotherhood, the group which propelled Morsi to power in the 2012 elections, has controlled the Gaza Strip, since 2007.
France has repeatedly broken the EU's fiscal rules and a top independent watchdog has said it doubts Paris will reach its target next year either.
Investigation team says launcher brought from Russia to east Ukraine fired missile that hit flight carrying 298 people
Palestinian President Mahmoud Abbas speaks about the dim prospects for peace with Benjamin Netanyahu’s Israel
Emergency services have arrived at the scene, with the number of people travelling in the helicopter unknown.
Libyan prime minister-designate Fayez al-Sarraj held talks with President Francois Hollande in Paris on Tuesday.
The joint manoeuvres in the strategic waterway between the Gulf and the Sea of Oman come after a series of incidents between Iranian vessels and US warships in the area in recent months.
Christos Stylianides says aid cannot be delivered "when convoys are deliberately shot at"
Libya is a key gateway for thousands fleeing turmoil for a better life in Europe
Statement from ETA terror group cites recent peace deal signed by FARC rebels, Colombian government
The wife of a prized MI5 intelligence officer Mrs Garbo had threatened to end the entire operation and expose the deception, by going to the Spanish Embassy and revealing her husband's activities.
Number of troops in Iraq as part of 60-nation anti-ISIL alliance now stands at 8,000, US official asserts
A new ambassador has been appointed to Cuba on the footsteps of once unthinkable changes to the relations of US and Cuba
Flotilla carrying women only sails off to Gaza Strip to end Israeli siege
German police investigate xenophobic motive after unknown suspects attack mosque in Dresden
America and NATO allies insist that retaining the right to launch a pre-emptive nuclear strike is a vital tactical option
Congress needs to pass measure by midnight Friday to keep federal government running