"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.
Malian President Ibrahim Boubacar Keita said wreckage of the flight had been spotted in his country's far north, toward the Algerian border between the towns of Aguelhoc and Kidal.
Spanish judicial authorities have sought the arrest and questioning of three U.S. soldiers accused of involvement in Spanish cameraman Jose Couso's death
The head of the Dutch police mission in Ukraine said it was difficult to get access to the site to look for more of the remains of the victims, many of whom were Dutch.
Udaltsov, who has been under house arrest since February 2013, and Razvozhayev were accused of coordinating the protests which turned violent on May 6, 2012
The U.N. Security Council unanimously adopted a resolution 10 days ago that authorized aid access at four border crossings from Turkey, Iraq and Jordan
More than 50 people have died so far in the violence that has deepened fears post-war Libya is slipping into lawlessness
Russia has in the past denied it is directly involved with the rebellion in its western neighbor, but the United States and its European allies accuse Moscow of arming and encouraging the uprising
"Gaps remain between the parties, so his focus is on finding a formula that both sides can accept," said the U.S. official
Since July 7, Israel has pummeled the Gaza Strip – from air, land and sea – with the ostensible aim of halting Palestinian rocket fire.
Pools of blood lay on the ground and on students' desks in the courtyard of the school near the apparent impact mark of the shell,
More than 75,000 made the trip in the first six months of the year, landing up in Italy, Greece, Spain and Malta, the UNHCR agency said. Their number included 10,500 children
The commander of U.S. troops stationed in South Korea last month said he had proposed deploying a THAAD advanced missile-defence system to the country
Politicians and activists have complained that while Ukraine has a new president, it has yet to elect a new parliament since the toppling of pro-Russian leader Viktor Yanukovich
Female asylum seekers with infants recently asked for bigger rooms so their children can learn to walk and crawl, as they are currently "confined in the extreme heat" in metal containers measuring 3m by 3m.
Shortly before the trial, Evans made a deal with prosecutors and admitted he had carried out more than 1,000 hacks involving some 200 victims
Ban's meeting with Shi'ite Grand Ayatollah Ali al-Sistani underscored the 83-year-old cleric's vast sway in Iraq, where Prime Minister Nuri al-Maliki is considered a polarising figure