At least 900 Israelis and more than 500 Palestinians have been killed after Hamas launched a surprise attack on Israel on Saturday morning.
Included in these figures is the 260 people massacred by Hamas gunmen at a music festival.
Fighting has continued over the weekend and into today, and has prompted retaliatory Israeli airstrikes.
Nearly 2,500 people have been injured in the attacks in Israel.
Hamas said that civilian hostages would be executed without warning and the killings broadcasted if Israel targets people in Gaza. The group claims to be holding more than 100 hostages, including Israeli army officers.
The Israeli Prime Minister Benjamin Netanyahu has vowed to turn Hamas strongholds "to rubble" and their Defence Minister has ordered a "complete siege" of Gaza.
More than ten British citizens are feared dead or missing in Israel.
WATCH NOW: Hamas attacks Israel
Nathanel Young, a 20-year-old soldier in the IDF from London has been killed in the Hamas attacks, his family have said.
His family posted online to say: "We're heartbroken to share that our little brother Nathanel Young was tragically killed on the Gaza Border yesterday."
At least ten other British citizens have been reported as missing or presumed dead.
Among those are Jack Marlowe, 26, who was working as security at the music festival, and Dan Darlington, a photographer, who is family understands to be dead.
An embassy spokesperson said of Marlowe: "He is missing, we don’t know for sure that he is taken hostage or dead or in a hospital."
Over 400 strikes have occurred on Gaza territory since yesterday.
Yesterday, amid the horrors, an Egyptian policeman has opened fire on Israeli tourists in the Mediterranean city of Alexandria, local media reports.
Two Israeli tourists and their Egyptian guide were killed, Israel's foreign minister has confirmed.
Earlier this morning, the Israeli air force claims to have struck the Hamas intelligence department.
A video shared by the air force shows huge plumes of smoke coming from the apparent Hamas HQ.
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Palestinians gather next to the ruins of Watan Tower, which was destroyed in Israeli strikes
Reuters
A spokesman has said that Israel is "still at war... still completing efforts to take full control of Israeli territory and communities from Hamas".
Meanwhile, Hamas has issued a call to arms to enlist more people in their fight against Israel.
As many as 100 Israelis have been kidnapped according to the Israeli Embassy in the US.
According to Israeli media, Palestinian fighters raided the settlements of Sderot, Be'eri and Ofakim.
The Lebanon-based Hezbollah militant group has claimed responsibility for an attack on the Israeli-occupied Shebaa Farms this morning.
The group have stated that they are "in solidarity" with Palestine.
Palestinians inspect the ruins of Watan Tower, which was destroyed in Israeli strikes
Reuters
WATCH NOW: Palestinians celebrate Israeli attacks at the Gaza border
Reuters
One of the areas they attacked included a piece of land in the Shebaa Farms - Lebanon claims it owns the area however Israel has occupied it since 1967.
The Israeli Defence Forces (IDF) have responded with artillery fire on southern Lebanon.
"The IDF has been taking preparational measures for this type of possibility and will continue to operate in all regions and at any time necessary to ensure the safety of the Israeli civilians," a spokesman said.
Hezbollah was one of the first groups to openly support Hamas' incursion into Israel yesterday.
The pope has called for an end to violence in Israel and Palestine.
He said that terrorism and war offer no solutions.
"War is a defeat, only a defeat. Let's pray for peace in Israel and Palestine," the pope said in his weekly address in St Peter's Square.
