The Israeli military has said for the first time that ground troops have been operating inside the Gaza Strip.

In a statement on Friday, the army said troops had entered Gaza to battle militants, destroy weapons and search for evidence about the missing hostages held by Hamas.

The announcement did not appear to be the beginning of an expected ground invasion of Gaza. Israel has been massing troops along the Gaza border since last Saturday’s deadly incursion by Hamas militants.

But later on Friday Israeli Prime Minister Benjamin Netanyahu vowed to destroy Hamas.

Mr Netanyahu delivered the threat in a nationally televised address.

“This is just the beginning,” Mr Netanyahu said. “We will end this war stronger than ever.

“We will destroy Hamas.”

He added that Israel has widespread international support for the operation.

Israel has been pounding Gaza with airstrikes since Hamas militants carried out the unprecedented cross-border attack, killing more than 1,300 people in a brutal rampage. Early on Friday, Israel ordered half of Gaza’s population to evacuate their homes.

It came as Palestinians began a mass exodus from northern Gaza on Friday after Israel’s military told some one million people to evacuate towards the southern part of the besieged territory, an unprecedented order ahead of an expected ground invasion against the ruling Hamas militant group.

The UN warned that so many people fleeing en masse — almost half the Gaza population — would be calamitous, and it urged Israel to reverse the order.

Families in cars, trucks and donkey carts packed with blankets and possessions streamed down a main road out of Gaza City, the biggest city, even as Israeli strikes hammered neighbourhoods in southern Gaza.

Hamas, which staged the brutal attack on Israel nearly a week ago and has fired thousands of rockets since, called on people to stay in their homes, saying the order was “psychological warfare” to break their solidarity.

The Palestinian envoy to the United Nations says his people’s mass exit from northern Gaza under Israeli military orders may compare to the displacement of hundreds of thousands of Palestinians amid the 1948 war surrounding Israel’s creation — an event that Palestinians call the “nakba,” or catastrophe.

Ambassador Riyad Mansour called the current flight “potentially a second nakba” as he spoke to reporters at UN headquarters on Friday before a meeting of Arab countries’ ambassadors.

While the evacuation order involves the northern part of the territory, Mr Mansour said “there is no place in Gaza that is safe”.

He called for a ceasefire to allow food, medicine and water into the territory.

And in a statement on Friday, Egypt’s Foreign Ministry condemned the Israeli army’s decision to tell people in Gaza to evacuate.

It said the move “constitutes a grave violation of the rules of international humanitarian law, and will expose the lives of more than a million Palestinian citizens and their families to the dangers of remaining in the open without shelter”.

In the statement, Egypt called on the United Nations Security Council, which was scheduled to meet on Friday, to stop the evacuation.

The UN agency for Palestinian refugees has shifted its Gaza centre of operations and some staffers to the territory’s south, but many of the world body’s 13,000 Gaza workers have chosen to remain in the north to continue helping people there, UN spokesperson Stephane Dujarric said on Friday.

The world body earlier warned of “devastating humanitarian consequences” after the Israeli military told the entire population of northern Gaza to leave.

Mr Dujarric said secretary-general Antonio Guterres and other UN officials have been working to try to get humanitarian aid into the sealed-off territory and to ensure that civilians are protected.

Asked what it would take for aid to start flowing, the spokesperson said: “What we need is the green light from the Israelis.”

Syria’s president on Friday called on countries of the world to stand together to stop “the crimes that Israel is committing against the Palestinian people”.

Bashar Assad made his comments during a meeting in Damascus with Iran’s foreign minister, Hossein Amirabdollahian, who is on a regional tour that has taken him to Baghdad and Beirut.

Mr Assad said the reason behind the latest wave of violence is that the Palestinian people have been prevented by Israel and Western countries from setting up their own state.

Mr Assad said Syria stands by the “legitimate” rights of the Palestinian people.

Mr Amirabdollahian later told reporters that Israel should stop the “war crimes it is committing before it’s too late”.

More than 3,000 people on both sides have died since Hamas launched its assault a week ago.