Like clockwork, every 30 seconds Israeli artillery goes into action against a barely visible target somewhere in the Hamas-ruled Gaza Strip.
Israel has vowed to “crush” Hamas after gunmen from the Palestinian Islamist group stormed across the border and killed 1,200 people — the deadliest attack on the country since it was founded 75 years ago.
Six days since the offensive took Israel by surprise, its army has kept pounding the densely populated Gaza Strip with artillery shells and air strikes, as it prepares for a possible ground invasion.
Israel has massed forces, tanks and other heavy armour around Gaza and called up 300,000 reservists.
In a statement on Thursday the army said it has bombarded Gaza with approximately 6,000 munitions containing a total of 4,000 tonnes of explosives since Saturday when it began striking Hamas targets.
Troops have deployed 150 mm artillery guns in fields along the border with Gaza, placing them a few metres (yards) apart, near the towns of Netivot and Sderot which were overrun by Hamas militants in their weekend onslaught.
Each time a salvo is fired, the ground shakes and a deafening noise fills the air.
On the front lines near the Gaza border, Netivot and Sderot are used to being targeted by rockets fired from the Gaza Strip, a tiny, densely populated enclave that is home to 2.4 million people.
On Thursday, two such rockets hit Sderot wounding four Israeli civilians, two of them critically.
“Soon, there won’t be anyone left to fight, to attack us, to spoil our lives,” said Tom, a 24-year-old reservist, deployed in the area.
Tom said he travelled from his home in Rishon Le Tzion near Tel Aviv to join up with his unit, in which his younger brother Adam also serves.
“I don’t know what I will do. But one thing is certain: we will wipe them off the map,” said Tom, still wearing shorts, a T-shirt and sandals, unlike Adam who is in uniform and toting an M-16 machine-gun.
“No one has killed Jews like that since the Holocaust,” Tom said.
‘It is war’
On Saturday, the Jewish Sabbath, hundreds of Hamas fighters crossed the Israeli border in a coordinated land, air and sea operation and killed 1,200 people
Most were civilians, killed in the street, in their homes and at a rave party, as a deluge of rockets from Gaza rained down on Israel.
Israel has retaliated by pounding Gaza with air strikes and artillery bombardments that have razed entire city blocks, with Palestinian officials reporting more than 1,350 dead, most of them civilians.
Israeli Prime Minister Benjamin Netanyahu pledged on Wednesday to destroy Hamas after announcing an emergency government for the duration of the war.
“Every Hamas member is a dead man,” he said.
“We will crush them and destroy them as the world has destroyed Daesh,” he said, using another word for the Islamic State group.
As soldiers fire their cannons at Gaza, volunteers from across Israel wearing helmets and bullet-proof vests hand out sandwiches and cool drinks to the troops.
“I will come back tomorrow and each day to bring them something good” to eat and drink, said Yuval, 49, who runs a transport company in the Israeli coastal city of Herzliya.
Avraham, 60, said he travelled to Netivot from his home in Netanya, north of Tel Aviv, to hug his three boys who have been mobilised to fight the Hamas militants “before they do what they have to do to these savages”.
“I am proud of them. They are like me, like all of us, they are afraid of nothing,” he said.
The army has set up roadblocks to stop infiltration by armed Palestinian militants into southern Israel.
In the skies above, Apache helicopter gunships fly at low altitude, before briefly breaching the airspace of the Gaza Strip.
On the ground, an Israeli Merkava tank rumbles close to the Gaza border, while in the distance black smoke billows over the enclave’s Rimal neighbourhood.
Journalists who tried to enter the Nahal Oz kibbutz, where women and children were killed on Saturday, are turned away by the military.
Young Israeli conscripts bluntly ask reporters to back off.
“There is nothing to see here. It is war,” one of them said.
“Come back when they are all dead in Gaza.”