Egypt has warned that it will not accept any further violation of its border with the Gaza Strip.
A government official said Egypt's borders were a red line that could not be crossed.
It came after Hamas said it was prepared to take action to break the Israeli blockade of the territory.
Militants destroyed parts of the Gaza border with Egypt in January, allowing hundreds of thousands of people stock up on much-needed supplies.
The unnamed official told the state-owned MENA news agency that Egypt was "capable of responding to any attempt to violate its frontiers".
A security official told the Associated Press news agency that Egyptian troops had been put on high alert.
On Tuesday, Hamas politician Khalil al-Haya described the situation in Gaza as "no longer bearable" and renewed threats to breach the border.
"I say clearly all options are open... What is coming will be bigger than what happened in the past, not only at the borders with Egypt but in other areas too," he told a news conference.
Israel tightened its blockade of the Gaza Strip when Hamas seized control of Gaza in June.
It says the blockade is necessary to prevent rocket attacks by Palestinian militants on Israeli communities near the border.
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