Residents close to the border think they can hear digging 19 months after the end of the last war

The scraping, scratching, grating sound could be an insect in the wall, a rodent under the floorboards, or the creaking of water pipes. Or it could be Hamas operatives digging under the earth from Gaza to Israel.

Some residents of the small communities along the Israeli side of the Gaza border believe they can hear the faint sound of tunnelling in the dead of night. Others are sceptical, saying fear and paranoia are fuelling imaginations.



But there is no doubt that, 19 months after the end of the last war between Israel and Gaza, in which the discovery of Hamas’s tunnels was declared a casus belli by Israel, large-scale digging has resumed.



Ismail Haniyeh, the Hamas leader in Gaza, has said so. This year he told the people of Gaza that Hamas fighters were “digging twice as much as the number of tunnels dug in Vietnam”.



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The Israeli military has also said so. “We can see Hamas digging from our [observation] posts. They aren’t trying to hide it from us,” a senior Israel Defence Forces official told the Guardian.



All reports and recordings of sounds heard by residents in the communities along the border with Gaza were investigated, he said. “We take every report from citizens and soldiers very seriously.”



But, he added: “As of today, we don’t know of any tunnels that have crossed the border into Israel.”



During the 50-day war in the summer of 2014, the extent and sophistication of Hamas’s underground network took Israel’s political and military leadership by surprise.



By the time a ceasefire held, the IDF said it had destroyed 32 tunnels that crossed under the border. It declared it had achieved the strategic goal of the conflict – but some were sceptical.



Brigadier-General Shimon Daniel, former head of the IDF’s combat engineering corps, said at the time: “Of course Hamas will try to rebuild the tunnels. The moment we go out [of Gaza] they will begin to dig.”



Since the war – in which the UN estimates Israeli forces destroyed or damaged nearly 100,000 homes – almost 3.5m tonnes of construction materials have entered Gaza through the Israeli-controlled Kerem Shalom border crossing, according to Israeli figures.



Israel says Hamas has diverted much of that from house-building to tunnel construction, assisted by a flourishing black market.



Last December, Hamas’s military wing, the Qassam Brigades, formed a special unit to dig and equip tunnels and train fighters to use them. Based on the cycle of conflict over the past 10 years, they are preparing for another war.

At least five tunnels have collapsed so far this year, killing 12 members of the Qassam Brigades and injuring dozens more. In one incident, seven people were killed east of Gaza City.

According to Gazan political analyst Mustafa Ibrahim, the Qassam Brigades are “using tunnels as a strategic weapon and intend to develop them and use them extensively”. In the 2014 war, Hamas believed it caused the IDF “substantial damage” by using its underground passages to carry out operations, he added.



The Islamic militant organisation has been engaged in tunnelling activity for at least a decade. IDF soldier Gilad Shalit was captured on the Israeli side of the border in a tunnels operation in 2006, and was held in Gaza for more than five years before being released in exchanged for 1,027 Palestinian prisoners.



These days, the tunnels fall into four categories. Some are intended to snake under the border, to be used for attacks on troops or civilians. Some are for holding rockets ready to be launched through the air from Gaza to Israel.



Many form part of a labyrinth of passages and bunkers beneath Gaza City, in which Hamas leaders and senior fighters can shield themselves in periods of intense conflict.



And a few are intended for smuggling arms from Egypt into Gaza, although the Egyptian army has destroyed most of the hundreds of tunnels which existed in the black market’s heyday.



The Qassam Brigades declined a Guardian request for an interview, but last month a military leader going by the name of Abu Hamza told the Hamas-linked al-Khaleej Online: “In any future confrontation, Israelis will be surprised by the strength and solidity of these tunnels, which can withstand Israeli shelling and concussion bombs fired by the Israeli aircraft or tanks.”



The tunnels, he said, could be used to “launch a large number of advanced rockets and mortar shells toward the Israeli towns adjacent to Gaza Strip, keep fighters away from Israeli radar, help them escape any Israeli attack and hide quickly when abducting Israeli soldiers.”



The IDF military chief of staff, Gadi Eizenkot, said this year that the tunnels were “at the top of the Israel Defence Forces’ priority list”.



The United States has provided $40m (£28m) this year “to establish anti-tunnel capabilities to detect, map and neutralise underground tunnels that threaten the US or Israel,” according to a report in Foreign Policy quoting US defence department spokesman Christopher Sherwood. There is talk of an underground “Iron Dome” to match Israel’s vaunted anti-rocket defence system.



Hamas has claimed that it has found sensors and cameras at the site of tunnel collapses, fuelling rumours in Gaza that such incidents are triggered by Israel rather than engineering miscalculations by Hamas.



The IDF refused to be drawn on such claims. “We are engaged in increased engineering work along the fence between Gaza and Israel. We are doing everything in our power to take out this specific weapon,” was all the senior IDF official would say.



He was at pains to point out the IDF’s successes. “In the last war, in 50 days we destroyed tunnels that took them years to build,” he said. And he added: “On any measure, the past year and a half since the last operation has been the quietest period we have seen for a long time.”



Not all Israelis living in small agricultural communities close to the Gaza border are reassured.



“There is fear and anxiety in the air,” said Arnon Avni, a graphic designer who has lived in Kibbutz Nirim, home to 360 people and about 2km from the border, all his life. “Everyone has some level of anxiety, but it’s different from person to person.



“This is partly a psychological war. Hamas is trying to frighten us – and they succeed. If you shake the stability of people’s minds, you are doing your work.”



Avni, who is firmly on the left of the Israeli political spectrum, described a recurring dream in which Hamas fighters advance on the kibbutz and he is powerless to protect his family and community.



“This is my nightmare. But my rational fear is that another round of war is coming.”



In Netiv HaAsara, a community so close to northern Gaza that you can clearly see into Palestinian neighbourhoods such as Beit Hanoun and Beit Lahia, tomato-grower Shaike Shaked reported increased military activity on both sides of the border in recent months.



“We need a break from wars, a rest. But the way things are going, it’s just a matter of time. If there is an infiltration, and they kill civilians in Israel, what happened in the last war is tiny compared to what would happen in this event,” he said.



“Personally, I don’t want to watch the reaction from Israel. The pictures [from inside Gaza] in the last war were so cruel that I don’t want to see another confrontation.”

