Security sources in Egypt confirmed to al-Arabiya that a cache of anti-tank missiles was discovered in a warehouse near the Israeli border. Among the weapons were six U.S.-made missiles that sources said may have been smuggled into the area from Libya.
Militants have used tunnels to ferry supplies across the border into Gaza to circumvent an Israeli blockade.
Egypt's Sinai Peninsula, meanwhile, has presented security challenges to the post-revolutionary government of Mohamed Morsi. Morsi in November, however, helped ensure a truce between Hamas, a rebel movement that controls Gaza, and the Israeli military.
Israeli airstrikes on Hamas-controlled Gaza killed Ahmed al-Jabari, commander of the Hamas military wing al-Qassam Brigades, during the conflict. Israel said it was responding to rocket fire from Hamas territory.
Amal Hamad, a member of the Fatah party, was quoted by Bloomberg News as saying a Friday rally in Gaza, approved by Hamas, was a message of Palestinian unity.
"And to tell Netanyahu, the Israeli premier, that the Palestinian state will be established soon whether he accepts it or not," he said.