CNN –
The Israel Defense Forces (IDF) said on Sunday it had discovered “the largest Hamas tunnel” in Gaza, spanning four kilometers (2.5 miles).
The IDF said the tunnel, which was secured “a few weeks ago” but opened to the public on Sunday, was wide enough to drive a large vehicle through, reached up to 50 meters underground and was equipped with electricity, ventilation and communication systems.
According to the IDF, it does not reach Israel, but ends 400 meters from the now closed Erez border crossing on the northern border between Israel and the Gaza Strip. Erez was stormed during the October 7 attacks.
The tunnel is part of Hamas' “strategic infrastructure” and will be destroyed, according to the IDF. In a video shared by the IDF, the Israeli military claimed the tunnel was created for Hamas troop movements and as a launching point for attacks.
Footage shared by the IDF and allegedly filmed by Hamas to show the construction of the tunnel shows a large vehicle entering the tunnel and a makeshift railway inside. CNN was unable to independently verify the footage or the IDF's claims.
In a statement on Sunday, the IDF claimed that the tunnel system was a project of Hamas leader Yahya Sinwar's brother, Muhammad Sinwar. The IDF provided no evidence to support this claim.
The IDF claims to have uncovered “hundreds of terrorist tunnel shafts across the Gaza Strip” and says it is working to “locate and destroy dozens of attack tunnel routes.”
Israel Defense Forces
The interior of a Hamas tunnel in Gaza.
Israel Defense Forces
IDF soldiers gain access to the tunnel.
Hamas has claimed to have built 500 kilometers (311 miles) of tunnels under Gaza, although it is unclear whether this figure is accurate.
The tunnels under Gaza are used to smuggle goods from Egypt, launch attacks on Israel, store rockets and ammunition, and house Hamas command and control centers.
Some of those taken hostage in the Oct. 7 attacks reported being taken to them and forced to march for hours.
Last month, the Israeli military discovered a tunnel shaft on the grounds of the Al-Shifa hospital complex, the enclave's largest medical facility. His discovery was central to the IDF's argument that there may be a network of tunnels beneath the hospital.
The hospital, the largest in Gaza, was stormed last month by Israeli forces who accuse Hamas of running a command center underneath. Hamas and hospital officials say it was only used to treat patients.
Separately, a US official told CNN on Tuesday that Israel had begun flooding some tunnels in the Gaza Strip with seawater to destroy the underground network, adding that they were “carefully testing” the method on a limited basis.
If successful, flooding could be increased to cause greater damage to the tunnel network.
CNN's Joshua Berlinger, Nadeem Ebrahim, Oren Liebermann and Sophie Tanno contributed reporting.