Rafah, Egypt ? Palestinians blasted holes in an Israeli-built wall and overwhelmed Egyptian troops on the Gaza border to flow by the hundreds into Egypt on Thursday, foiling attempts to impose control after days of unhindered crossings.

Israeli and Palestinian leaders expressed fears that militants and al-Qaida terrorists will infiltrate Gaza and Israel through the border, which has been open since Israeli troops withdrew from the Palestinian territory.

Egypt had promised to reimpose border controls by Thursday evening, and in the morning several hundred policemen were deployed at the main crossing points – more than the few dozen seen over the past days. They allowed Palestinians to return to Gaza and managed to slow the number entering Egypt to a trickle for part of the day.

But after hours of pushing and shoving at the Saladin border crossing in Rafah, the police line broke and hundreds of Palestinians crossed the border. Faced with the large crowds, many policemen gave up and the crossing became almost as open as it was in the past days.

The so-called Canada crossing was closed by police – but less than a mile away, hundreds of Palestinians passed through an olive grove and crossed freely through a break in the wall at the border.

Egypt has yet to deploy the bulk of the 750 border guards it promised to station on the frontier under a deal with Israel. A local official said it could be another three days before the guards, who are more heavily armed than the police, are in place.

Palestinians pass sheep from the Egyptian side of the border to the Palestinian side in the Rafah refugee camp Thursday in the southern Gaza Strip.

To avert friction, Egypt wants the flow of people to subside before it brings in the soldiers, said the official, who is part of the Rafah government and spoke on condition of anonymity because he was not authorized to release the information.

Palestinian security forces also were struggling to control the number of Gazans crossing, especially with the many breaches opening up in the high wall Israel had built along the border.

The militant Palestinian group Hamas blasted a hole in the wall north of Rafah before dawn Thursday to help people get through. In the afternoon, a second explosion blasted a hole about a mile further down the wall, reportedly by the group Islamic Jihad.

Israel’s Foreign Ministry expressed fears that international terrorists will exploit the chaotic border to infiltrate Gaza and Israel.

“We’re talking about Iran, we’re talking elements in Syria, we’re talking about groups like Hezbollah and we’re talking also about international terrorist groups like al-Qaida,” said spokesman Mark Regev. Israel has long accused both Iran and Syria of sponsoring militant groups.

Israel, which withdrew its last troops from Gaza on Monday, is also concerned that Palestinian militants might slip into Egypt, then infiltrate Israel across the long, lightly guarded Israel-Egypt border – bypassing the fence between Gaza and Israel.

Rafiq Husseini, the top aide to Palestinian leader Mahmoud Abbas, said the Palestinian leadership is “even more worried than Israel about al-Qaida coming here because al-Qaida will harm us more than Israel.”

Such a presence, he said, would hurt prospects for peace and renewed negotiations with Israel.

Gazans, meanwhile, reveled for another day in their new freedom after years of Israeli travel restrictions. Many store shelves in the Egyptian side of Rafah were cleaned out as Palestinians continued their shopping spree.

Black marketeers in Gaza reported a drop in prices for AK-47 assault rifles and Egyptian-made pistols because of the large quantities of firearms entering the territory.