After a devastating weekend of attacks in Israel, that tore through Jewish and Palestinian communities causing panic and destruction, the Israeli military said it had called up an unprecedented 300,000 reservists and was imposing a total blockade of the Gaza Strip. It's a sign it may be planning a ground assault in response to the shock assault by Hamas.
After hours of intense bombardment by Israeli jets, Hamas, the Islamist movement which controls Gaza, threatened to execute a captive if civilian houses were bombed.
Inside Israel, Palestinian fighters were still believed to be holed up in several locations, two days after they killed hundreds of Israelis and seized dozens of hostages in a raid that shattered Israel's reputation of invincibility.
The Dean of St George’s College in Jerusalem, Richard Sewell, tells Premier he had to shelter a group of pilgrims who were with him on a visit to the Holy Land when the fighting broke out: "On Saturday, when the violence erupted, we had to keep our pilgrims in the safest room in the college, which actually was the library.
"We stayed together for most of the day in that room... praying and singing together, and trying to just keep our spirits up and keep a sense of perspective in the midst of a very, very frightening time for everybody." The group has left Jerusalem for a different location, and Sewell says his thoughts are with all those caught up in the fighting.
Hamas, which calls for Israel's destruction, says its attack was justified by a 16-year blockade against Gaza, described by some as an 'open-air prison', and the deadliest Israeli crackdown for years in the occupied West Bank.
Israeli TV channels said the death toll from the Hamas attack had climbed to 900.
In Gaza, Israel pressed on with its most intensive retaliatory strikes ever, which have killed more than 500 people since Saturday. Defence Minister Yoav Gallant announced a tightened blockade, which would prevent even food and fuel from reaching the strip, home to 2.3 million people.
Tens of thousands of people are being displaced by the fighting. Palestinians reported receiving calls and mobile phone audio messages from Israeli security officers telling them to leave areas mainly in the northern and eastern territories of Gaza, and warning that the army would operate there.
As night fell on Monday, the Israeli air strikes became more aggressive and witnesses said several Hamas security headquarters and ministries were hit.
Netanyahu told mayors of southern towns hit by Saturday's surprise assault that Israel's response would "change the Middle East".
Accordingn to Reuters, at the Jabalia refugee camp in northern Gaza, men clambered on a pancaked building to pull an infant's tiny body from the rubble, carrying it down through the crowd below amid still-smouldering remains of bombed buildings.
Qatari mediators have held urgent calls with Hamas officials to try to negotiate freedom for Israeli women and children seized by the militant group and held in Gaza, in exchange for the release of 36 Palestinian women and children from Israel's prisons, a source told Reuters.
An Israeli official said no negotiations were under way.
Israel's military faces harsh questions for the country's worst intelligence failure in 50 years. Netanyahu's options may also be curtailed by concern over the fate of Israeli hostages.
Richard Sewell tells Premier tension in the region has been brewing for a long time: "Although it came as a surprise, and even a surprise to Israeli intelligence services, and there will be hell to pay for that for the oversight... it could have happened anytime in the last few years, even the last 20 years."
He says the violence cannot be condoned, and urges Christians to pray for all sides: "We have to pray with the deepest compassion for every single person who suffers and pray for an end to violence. We're praying for justice. We're praying for that deep peace which is not simply the absence of war, but it is a place where people can live in dignity, and reconciliation.
"And we should not be siding one against the other, but praying into the situation for the peace that passes all human understanding, to filter into the hearts and minds and lives of everybody, every cherished human being who lives in this land. All of them are children of God. And if we lose sight of that, I feel we have ceased to pray with the heart of Christ."
(additional reporting by Reuters)