Israel closed off the tiny coastal strip and its 1.5 million residents after it was overran by fighters from Hamas, a movement sworn to the destruction of the Jewish state.

With the territory completely dependent on imports for food, fuel and supplies, its residents are now flooding to stores and gas stations amid rumours that supplies will soon run out.

"More and more people are coming, buying everything to store in their house," said Samir Nasser, the owner of a small supermarket in western Gaza City. "They are afraid of a prolonged Israeli closure."

"For the moment we have fuel, but we don't know if this fuel will last for several days," said Mahmud, who works at a petrol station in Gaza City. "The people are afraid that with an extended Israeli closure, it will run out."

And Israeli army radio reported on Sunday that the country had deliveries of fuel to Gaza.

The new rulers of Gaza have sought to play down rumours of dwindling food supplies, branding them "propaganda," but admitted that a continued closure of the territory by Israel was dangerous.

"Israel can't keep its closure of the crossings for a long time," Hamas spokesman Sami Abu Zuhri told AFP.

"It's very dangerous if they keep doing so and we will not remain silent," he said, declining to say what steps the radical Islamists would take.

While some Gazans stocked up on supplies, others sought to flee the impoverished territory already reeling from an economic aid boycott where 80 percent of the population depends on aid.

About 500 Palestinians, mostly women, children and the elderly, were gathered on Sunday at the main Erez border crossing with Israel, sitting on suitcases in the baking sun without food or water, witnesses said.

When one of them approached too close to the Israeli side of the crossing, an Israeli soldier warned them over a loudspeaker "Stay Away." The previous day Israeli soldiers fired in the air to keep people away.

About 700 metres (yards) away from the crossing, fighters from Hamas's armed wing had set up a checkpoint, turning away anyone else who tries to set up shop at the crossing, sending them back into Gaza where residents fear for their future.