Israel targets Hamas subterranean 'city', key in Gaza war

A sprawling network of Hamas tunnels under the Gaza Strip has become a primary target for the Israeli military in its stated mission to defeat the Palestinian militants, experts say.

The army said Saturday its forces had struck 150 "underground targets" in a night-time blitz on Gaza that destroyed "terror tunnels" and "underground combat spaces", and killed Hamas fighters.

Since Hamas gunmen stormed into southern Israel on October 7, launching raids that Israel says have killed 1,400 people, the military has stepped up urban warfare training at a desert base where a replica Gaza town had been built.

Israel also says more than 220 people abducted from Israel and now feared held in the tunnels.

Gaza's Hamas-run health ministry says that more than 7,700 people, including more than 3,500 children, have been killed in Israeli strikes during three weeks of war.

The Hamas military wing says that some 50 hostages have already been killed in the raids, a claim AFP could not independently verify.

In past violent flare-ups and wars, Israeli jets have hit parts of the massive tunnel network which Hamas has steadily developed and rebuilt for years, often referred to by Israeli soldiers as the "Gaza Metro".

The military has constantly searched for new weapons to destroy the shafts that some experts say extend 500 kilometres (300 miles) under the roughly 40-kilometre-long territory.

Israeli daily Maariv this week called it an "underground hell" as Israeli prepares for a widely-expected land invasion over the shock October 7 attacks.

Yocheved Lifshitz, 85, one of four hostages -- all women -- released so far by Hamas, said after returning to Israel that she had been forced to walk in a "spider web" of tunnels.

John Spencer of the Modern War Institute at elite US military academy West Point, described "a veritable city underneath the cities on Gaza's surface".

- 'Wicked problem' -

"Tunnels will be the vital element of Hamas's guerrilla warfare strategy" against Israeli soldiers, Spencer said in a study released this month.

Some shafts go as deep as 40 metres (130 feet) and are able to withstand 1,000-pound (455-kilo) bombs, according to the Israeli army.

As Israel pummels the narrow territory mostly from the air, Hamas bets on the relative safety of the tunnel network -- parts of which have extended beyond Gaza's borders into Egypt and Israel -- for its fighters and leaders, as well as to store weapons and basic supplies, according to experts.

Spencer called the tunnels a "wicked problem" for Israel's military, "for which no perfect solution exists".

Tunnels into Egypt have been used to smuggle arms, food and alcohol into Gaza, under a crippling Israeli-led blockade since Hamas took power in 2007. Egypt had flooded some in a bid to destroy the network.

In 2006, less than a year after Israel unilaterally withdrew troops and settlers from Gaza, Palestinian fighters crept out of a tunnel and abducted an Israeli soldier, Gilad Shalit. He was held by Hamas for five years before being released in a prisoner exchange deal.

Israeli forces in past ground invasions, in 2008 and 2014, targeted the Hamas subterranean network, but by 2021 -- when Israel said it had destroyed 100 kilometres of tunnels -- underground routes were estimated to be more than five times that figure, according to Spencer.

During the 2021 war Israel sought to trick Hamas, including via press statements, into believing it would launch a land invasion so that fighters rushed to hide in tunnels. Intense air raids followed.

Israel is convinced Hamas leaders still have their war rooms and living quarters underground and stock weapons there.

- 'Right place, right time' -

The training at the Israeli desert base includes fighting off attacks launched from hidden entrances. Spencer said Hamas fighters may "move underground, pop up, strike, and pop quickly back into a tunnel".

According to the military expert, "Hamas will have already placed its leadership, fighters, headquarters, communication, weapons, and supplies like water, food, ammunition in its tunnel complexes to prepare for the ground assault."

The tunnels have their own power supply, ventilation and food and water stocks, observers say.

Hamas can "exploit its subterranean network to move fighters to the right place at the right time –- or to move them away from threats they cannot handle effectively," said Mick Ryan, a retired US army general now an analyst for the Center for Strategic and International Studies in Washington.

Israel has trained specialist commando engineers to find and destroy tunnels, Western experts said. The army has even given dogs special training for working underground.

Its Yahalom unit it one of the world's largest "that trains, mans, equips, experiments and develops new ways to deal with underground warfare", said Spencer.