Inside the biggest Hamas tunnel ever found: Israel releases video from giant underground labyrinth that was built by terror chief's brother and spans 2.5 miles beneath war-torn Gaza

Israel has revealed what it says is the biggest tunnel its troops have ever discovered, as its army works to expose and destroy Hamas terrorists' sprawling underground city known as 'the Gaza Metro'.

Thought to stretch some 300 miles beneath the embattled enclave, Israeli soldiers have painstakingly sought to locate every entrance to every passageway in the 'spider's web' of tunnels and make them unusable.

The network was instrumental to Hamas in organising the October 7 atrocities, which saw its fighters storm across the Israeli border and murder 1,200 people, and has been used as a hiding place for terrorists and their weapons.

Israel's Defence Forces spokesperson has now given journalists a tour of the extensive tunnel, which spokesperson Daniel Hagari said is wide enough to fit a car through and spans well over 2.5 miles (4km). 

He said the tunnel had been built in order to carry out a terror attack, with its end just 400 metres (1,310ft) before the Erez Crossing - the barrier Hamas and other Palestinian terror groups smashed through to launch their bloody attack on Israel more than 70 days ago. 

Hagari told reporters that this tunnel system alone cost 'millions of dollars', adding that it had been a project led by Mohammad Sinwar, the brother and right-hand man of Hamas leader Yahya Sinwar, and commander of Hamas' Khan Younis Battalion.

'We are going to enter the biggest tunnel we have found in Gaza, the biggest secret of [Mohammad] Sinwar, his subterranean tunnel project,' the commanding officer said as he led a triumphant tour of the underground lair.

The IDF has vowed to hunt down and kill Sinwar, who they say is hiding 'deep underground'. 

IDF spokesperson Avijaa Adraei explained how the giant tunnel was unearthed.

'Attack operations were launched from the aforementioned tunnel targeting our forces during the fighting in the Gaza Strip,' he said.

'A few days ago, saboteurs were spotted inside the tunnel, and thus the IDF forces eliminated them.'

Israel has also released astonishing footage which it says shows the construction process behind the cavernous passage ways.

Video clips show workers drilling into the walls to expand the passageways and what appears to be their bosses being given a tour of the extensive route.

Discussing the lengths Hamas has gone to in order to establish its huge network, Lt. Col. Richard Hecht said: 'Hamas has persistently and deliberately invested enormous amounts of money and resources into terrorist tunnels that serve only one purpose - attacking the State of Israel and its residents. 

'This strategic attack tunnel network, large enough to drive vehicles through, was spearheaded by Muhammad Sinwar and intentionally dug near a crossing dedicated to the movement of Gazans into Israel for work and medical care,' the IDF spokesman went on. 

'For Hamas, attacking the people of Israel continues to take priority over supporting the people of Gaza.' 

It comes after Israel earlier released footage which shows what it claims is the entrance to a tunnel being concealed beneath a baby's cot.

Troops in the Nahal Infantry Brigade's 931st Battalion said they came across the tunnel shaft opening in a home in the Jabaliya refugee camp in northern Gaza.

A company commander in the 931st Battalion gives a tour of the home, revealing where the soldiers found the tunnel.

The IDF says the underground passage is a 'strategic' Hamas attack tunnel, and following its discovery the route was later destroyed by combat engineers.

Some of the tunnels in the extensive network are buried as far as 40ft underground.  

They are used by Hamas fighters to ambush unsuspecting Israel troops, and can be booby-trapped or filled with explosives so they are primed to cave in if entered by enemy forces.

Since it launched its offensive in Gaza following the October 7 attacks, the IDF says it has exposed hundreds of terror tunnel shafts throughout the Strip. 

Many it has come across have been built from reinforced concrete and are equipped with electricity, ventilation, sewage, communication networks and rails, the IDF said. 

The tunnels are also often constructed under 'sensitive sites' such as hospitals, schools, and mosques, according to the IDF, which has accused Hamas of using civilians as 'human shields'. 

Israel has recently received a supply of 2,000-pound 'bunker buster' bombs designed to penetrate the ground and wipe out the tunnels, according to a report by The Wall Street Journal.

Washington transferred 100 of the BLU-109 bombs to Israel, weapons that are designed to break through hardened structures before exploding, the report said.

Another tactic Israel could soon be using would be to pump seawater into the tunnels in an effort to flush the terrorists out of their underground lair.

Israel is said to have installed at least five pumps about a mile from the Al-Shati refugee camp in the north of the coastal enclave that could move thousands of cubic metres of water per hour.

On Thursday, the Times of Israel reported that a trial of the flooding method was a success - adding to fears that any Israeli hostages or innocent Palestinians inside the tunnels could be killed.

Israel has been accused of failing to do enough to protect civilian life as it tries to root out Hamas.

Israel has continued to strike what it says are militant targets in all parts of Gaza, despite earlier telling residents to find safety in the south.

Its onslaught has killed at least 18,800 people, mostly women and children, according to the territory's Hamas government. 

It comes after the IDF released dramatic bodycam footage showing the moment an Israeli soldier throws a hand grenade down a tunnel shaft as he comes face-to-face with Hamas fighters in the north of the Gaza Strip.

Bitter fighting continues between Israel's Defence Forces and Hamas despite growing international and domestic pressure to scale back the offensive in the besieged enclave.

Israel's air and ground assault has seen it target some 200 targets in the past day, including several apartments used by Hamas in the Gaza City suburb of Shejaiya, where it said paratroopers found stockpiles of weapons. 

During its operations in the area, a soldier in the IDF's 188th Brigade filmed himself tentatively approaching a tunnel shaft before a terrorist breaks cover to shoot at him and his comrades from inside. 

They start to return fire before the soldier tells the others to hold off as he pulls the pin on a grenade, throwing it into the tunnel. 

The IDF said the close-quarters combat was successful and that its troops 'neutralized the terrorist and destroyed the tunnel shaft.'