Although Islamic militant group Hamas, which governs the Gaza Strip, has strongly condemned the killing of Egyptian guards at the border with Israel and Gaza yesterday, many Palestinians in the enclave still blame the group for not doing enough to exert control over the border. 

Gunmen disguised as Bedouins attacked an Egyptian border post yesterday, killing at least 16 guards and soldiers. The attackers then hijacked two armored vehicles and stormed the border with Israel. One was destroyed by Israeli attack helicopters, while the other exploded when it came into contact with an evacuated Israeli border post, but several of the gunmen remain at large

The incident could strain the relationship between Egypt's newly empowered Muslim brotherhood and Hamas, an offshoot of the Egyptian Islamist group, if it turns out that the gunmen came from Gaza as Egyptian officials have alleged. 

Israel and Egypt have closed their official border crossings with Gaza until further notice, and Egyptian and Hamas officials have shut down the hundreds of tunnels that are used to smuggle food, fuel, and construction materials to the Israel-blockaded seaside territory because Egypt believes that the gunmen tried to escape into Gaza through them. 

Gazans get a major percentage of their goods through the smuggling tunnels between Egypt and Gaza, and news of the closure of both the border crossings and tunnels panicked residents, bringing back dire memories of a tight Israeli blockade that deprived the area of many daily needs before the tunnels were dug. 

In Gaza City, cars lined up in front of gas stations to refill in preparation for an expected shortage and people flocked to markets to stock up on goods after rumors spread that the Egyptian military planned to destroy the tunnels.

"Only God knows when the border will open again," says Um Khaled, a teacher, as she bought canned beef and sardines in Gaza's old market. "The Egyptians have helped us a lot. They opened the borders for us and let the tunnels work around the clock. Killing [the Egyptians] should not be the reward."

She urged Hamas to bring the remaining attackers to justice if they really were from Gaza. Military actions against Israel or Egypt always cause disasters for ordinary people, she says. 

Taxi driver Mahmoud Sa'ad says he fully believes that Hamas has no links with those who killed the Egyptian soldiers, but he blames Hamas for allowing them to move freely in and out of Gaza.

"Everyone well knows that those radical Islamists have influence in Sinai and that they move freely on both sides using the tunnels that are controlled by Hamas. Hamas should have got rid of them long ago because now they are harming their own interests," Mr. Sa'ad says.

Israel has always warned that the Sinai is a staging ground for militants, and its warnings have increased amid deteriorating security on the sparsely populated desert peninsula since former Egyptian President Hosni Mubarak was ousted last year. 

Despite Egypt's accusations that Palestinians were behind the attack, Gaza's Hamas-led government denied that any of the Palestinians factions in the enclave had any role in the operation. 

"We only fight Israel. And when we fight it, we start the fight from our territories," said Islam Shahwan, a spokesman for the Gaza Interior Ministry. "We have blocked the tunnels and are looking for any infiltrators," he added. 

Mukhaimar abu Saada, a professor of political science at Gaza's Azhar University, believes Hamas is responsible for the infiltration of militants into Egypt because it controls Gaza and guards its borders. 

"If Gazans were among the killers of Egyptians soldiers, then Hamas is to blame simply because it has always given them a green light to use the tunnels for both transportation and arms smuggling," Mr. Abu Saada says.

But Hamas would not risk involvement in such an attack, he says. As an offshoot of Egypt's Muslim Brotherhood, now Egypt's leading political force, Hamas now has close ties to the Egyptian government. Mohamed Morsi, Egypt's new president, was a longtime member of the Muslim Brotherhood, and only left it at the outset of his time in office.