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Israel’s military has developed a range of specialist tunnel fighters including killer drones and attack dogs to take on Hamas’s huge underground network.
Officials on Tuesday revealed its forces attacked Hamas gunmen inside the vast tunnel network beneath the Palestinian enclave, estimated by some to rival in length London's Tube network.
Specialist teams made up of the Oketz or “Sting” dog units and the Samur “Weasel” subterranean commandos have been training in a specially built tunnel complex in the Negev Desert to take on the 500 kilometres of the “Gaza metro” built by Hamas.
Defence analysts have disclosed that Israel has used ground-penetrating radar and gravity detectors to map out the spiderweb system precisely.
With Israel’s declared aim to destroy Hamas in retaliation for the attacks on October 7 that killed 1,400 people, taking on the tunnel network will be key. A statement on Tuesday said the targets of the operation had expanded to "military compounds inside underground tunnels belonging to the Hamas terrorist organisation".
Israeli Prime Minister Binyamin Netanyahu has vowed to eliminate Hamas in all combat arenas. “All operatives must die, above ground, underground, inside Gaza and outside,” he said in a broadcast earlier this month.
The dangers of tunnel fighting are extremely high and the Israelis will be determined to keep their casualties to a minimum.
Hamas has been building the labyrinth for almost a decade, with some tunnels dug up to 70 metres below ground, for storing weapons, fuel and food, but their destruction is vital for any Israeli success.
As a result, they have formed a force of combat engineers called the Yahalom “Diamond” that have trained to locate tunnels and either destroy them or allow for a “hard entry”.
If entry is required, then the Samur and Oketz units will drop into the entrances that would likely have been blown open, and enter the tunnels that are made of reinforced concrete and are 1.8 metres high and one metre wide.
Robots will be used ahead of any tunnel assault, with the Tel Aviv company Roboteam spending the last decade developing specialist unmanned ground vehicles for the operation.
This will include the small IRIS robot that soldiers call a “throwbot”, with its ability to drive down tunnels relaying pictures back to its operator, using specialist sensors to detect objects and people.
It is also understood that Israel has developed a robot similar to the US Marines' Gladiator tactical tracked drone that has sensors and carries a 7.62mm squad automatic weapon.
The robots will also be able to use their sensors and equipment to find and potentially detonate booby-traps planted by Hamas.
Behind them will come the “Weasel” commandos, who are specially selected troops able to tolerate the enclosed and claustrophobic conditions. Israeli defence sources said they were usually introverted characters with the ability to keep a “psychological distance from the situation”.
Tunnel combat is also described as akin to underwater fighting because kit used on the surface, such as thermal imaging, or surveillance or navigation systems, will not function underground.
Defence analysts also believe the Israeli army could develop tactics used by Ukraine in its fight against Russia by deploying airborne drones inside the tunnels, some equipped with small bombs.
“Both sides will be attempting to surprise each other and they will have surprises up their sleeve,” said Brigadier Ben Barry, an urban warfare specialist at the IISS think tank.
“The Israelis also have advantages with the biggest urban training facility of any armed forces in the world training people to fight in tunnels but also using drones and robots to take the first hit. The Israelis have all sorts of technological gadgets.”
They also have specially trained military dogs in the Oketz canine unit, most likely led by the highly intelligent and aggressive Belgium Malinois favoured by British special forces.
The dogs will be able to sniff out explosives, find entrances and attack armed personnel by biting their arms.
Hamas has used 900 full-time workers to build the system, according to the Rand Corporation, and is also reported to have sent engineers to Iran to learn about providing electricity, ventilation and water in deep command bunkers.
In the first instance Israel will most likely attempt to destroy tunnels using its powerful GBU-28 bunker-buster bomb that weighs 2,300kg and can penetrate up to 30 metres.
However, Israeli bombing has caused more than 8,500 Palestinian civilian deaths, according to the Hamas-run Health Ministry in Gaza.
Israel will also use cement or blocking agents such as sponge-bombs that can rapidly seal a tunnel, in which two liquids come together and expand into an impenetrable foam.
Tunnel combat will be “physically and mentally challenging” because of the need to operate with very short lines of sight, said Brig Barry.
“Identifying and tracking both adversaries and friendly forces is difficult and troops are easily separated, movement is canalised and highly constrained,” he added.
“But I’d be very surprised if the Israelis hadn't a well thought-out approach to the tunnels, some of which is not in the public domain.”
Israel’s likely siege tactic in Gaza could also force Hamas to the surface if they run out of fuel for generators that provide lighting and air underground.
“I expect their doctrine is to just block up and move on or fully clear those that need to be cleared,” said Sam Cranny-Evans, of the Rusi think tank.