Palestinians lead a donkey cart past a destroyed section of the border wall Friday in Rafah, southern Gaza Strip, on their way to Egypt. Egyptian border guards with riot shields formed human chains Friday, trying to hinder the flow of Gazans into Egypt in an apparent attempt to gradually reseal the breached border, but thousands of Palestinians managed to pass through.

Rafah, Gaza Strip ? Hamas-backed militants driving bulldozers knocked down more fortifications Friday along the Gaza-Egypt border – a brazen challenge to Egyptian riot police, who abandoned their positions after attempting to reseal the frontier using human chains, dogs and water cannons.

Militants in black clothing, some of them masked, stood atop a bulldozer as it knocked down concrete slabs under the watchful eyes of Hamas security officials, who turned a blind eye and were later seen patrolling on the Egyptian side of the border.

Thousands of Palestinians flooded into Egypt, pushing through several openings as Egyptian troops retreated to their bases on the other side of the border. Palestinians positioned cranes next to the border and lifted crates of supplies into Gaza, including camels and cows.

Hamas, after blasting open the border wall earlier in the week, offered further proof Friday that it simply cannot be ignored – driving home in no uncertain terms that a high price will be paid by anyone who seeks to shape Gaza’s border arrangements without the militants’ consent.

The day’s events also underscored a great dilemma faced by Egypt: if it acts forcefully against the Gazans, it could anger its own people, who are sympathetic to the Palestinians’ plight. But if it does nothing, it risks infiltration by Islamic militants.

Earlier Friday, Hamas gunmen fanned out along the Gaza side of the border, attempting to create order. For the first time since the border wall was torn down in a series of blasts on Wednesday, Gaza’s Hamas rulers deployed their most elite forces to contain the rowdy crowd.

Hamas is clearly seeking to flex its muscles ahead of a potential new border agreement with Egypt that the militants hope will help end a 2-year-old blockade imposed by Israel and the West.

The group called for a three-way meeting among Hamas, Egypt and the Fatah movement of President Mahmoud Abbas to try to come up with a new border arrangement for Gaza.

“If the leadership in Ramallah refuses this call, we will not stand idle until the siege overruns life in Gaza,” Hamas said in a statement.

The border breach provided a significant popularity boost to Hamas, which can claim it successfully broke through the closure that has deprived the coastal strip of normal trade and commerce.

“Hamas did this and when Egypt found resistance, it let up,” said a joyous Reem Sahloul, 28, of Khan Younis. “Hamas proved stronger than the (Egyptian) army.”