Egyptian riot police and armored vehicles blocked Gaza cars from entering Egypt on Saturday, a day after Hamas operatives using bulldozers had widened a border breach to make it easier for vehicles to cross. Dozens of riot police formed human chains, blocking two passages through the breached border used by cars, and several Egyptian armored vehicles took up positions to back up the troops. Two more armored vehicles blocked roads in the Egyptian border town of Rafah. The deployment marked the second attempt by Egypt in two days to regain control over the border, which was breached Wednesday when Hamas blew down the border wall, allowing hundreds of thousands of Palestinians to flood into Egypt. Egyptian guards with riot shields formed human chains along the Egypt-Gaza border Friday, but were unable to stop hundreds of Palestinians from rushing into Egypt after a bulldozer wrecked another section of fence along the frontier. Men in black clothing, some of them masked, stood atop the bulldozer as it knocked down a concrete slab under the watchful eyes of Egyptian forces on the other side who shot in the air in an attempt to hinder the flow of Gazans into Egypt. Thousands of Palestinians, many of them carrying empty fuel canisters, managed to push through several openings despite the presence of the Egyptians deployed nine rows deep in some places. At one point, guards aimed a water cannon above the heads of people, not at them, to keep them back. Cranes were positioned next to the border, lifting crates of supplies over into Gaza. Egyptian forces took up positions a few steps into Palestinian territory, using shields to protect themselves from some Gazans who climbed atop car roofs and threw stones at them. Witnesses said a photographer was lightly injured in the clash. The influx included a gaggle of Palestinian women in finely embroidered dresses and fresh makeup, heading to relatives' weddings in Egypt they said had been hastily moved up to allow Gazan family members to attend. Yousef Mohammed, 17, from Gaza, said he had waited until Friday to make the trip because he was trying to get together enough money first to shop in Egypt. "They don't want us to go in," he said, pointing at the riot police. Egyptian Amira Ali, 39, carrying her toddler son and holding a 6-year-old son by the hand, said she wants to visit her mother-in-law in Gaza. "Of course, I'm afraid (of being trapped in Gaza), but will try to go for a while so my mother in law can see the kids," she said. Travelers returning from Egypt said they heard loudspeaker announcements there that Gazans had to return home by 7 pm (1700 GMT) Friday. The border was breached Wednesday, when Palestinians blew down large sections of the border wall. Since then, Egypt has allowed tens of thousands of Palestinians to go back and forth, but has rejected any suggestion of assuming responsibility for the crowded, impoverished territory. In an interview published Friday, President Hosni Mubarak called the situation in Gaza "unacceptable" and called on Israel to "lift its siege" and "solve the problem." "They should get things back to normal according to previous agreements and understandings," Mubarak told the weekly Al-Osboa. He also invited rival Palestinian factions to Cairo for talks, but did not mention a date. The opening of the border, even if temporary, provided a significant popularity boost to Gaza's Hamas rulers, who can claim they successfully broke through the internationally supported Israeli closure that has deprived the coastal strip of normal trade and commerce for nearly two years. Both Egypt and Israel restricted the movement of people and goods in and out of Gaza after Hamas won parliament elections in 2006, and further tightened the closure after Hamas seized control of the area by force last June. A handful of black-clad Hamas gunmen fanned out along the Gaza side of the border Friday, attempting to create order amid waves of Gaza residents approaching the area. It was the first time since the border fence was torn down that Hamas deployed uniformed men to deal with the chaos. The group has been using plainclothes agents to regulate the crowd. The gunmen attempted to prevent cameramen from filming at the border area, at one point threatening journalists.