Fighting in Gaza has entered day 21 after the Palestinian group Hamas launched a surprise cross-border attack on Israel, killing about 1,400 people.
Since the October 7 attack, Israel has been bombarding Gaza, in which more than 7,000 Palestinians have been killed.
The Israeli military has also mounted an incursion deeper into Gaza on Friday as it readies for a ground offensive against Hamas.
However, one of the biggest challenges the Israeli troops face is an extensive Hamas tunnel network, where the hostages have been reportedly kept.
Hamas reportedly has different kinds of tunnels, hundreds of kilometres long and up to 80 metres deep, running beneath the sandy 360-sq-km coastal strip and its borders.
Sponge bombs: Israel’s new secret weapon to get into Hamas tunnels
In order to fight Hamas through its tunnel network, Israel is reportedly making ‘sponge bombs,’ which create a sudden explosion of foam that rapidly expands and then hardens.
According to a report in The Telegraph, Israel has been testing the chemical grenades, which contain no explosives but are used to seal off gaps or tunnel entrances to block occupants.
These devices are said to be encased within a protective plastic container that has a metal barrier that divides two distinct liquids.
When activated, these liquids merge and advance.
The Israel Defense Forces (IDF) were seen deploying these devices during exercises in a mock tunnel system near the Gaza border in 2021.
Among the elite units tasked with going underground is ‘Yahalom,’ specialist commandos from Israel’s Combat Engineering Corps known as the ‘weasels,’ who specialize in finding, clearing, and destroying the tunnels.
How Hamas built its tunnel network
Hamas, formed in Gaza in 1987, reportedly started digging tunnels in the mid-1990s. Hamas’ network of tunnels is a key strategic advantage it has over Israel in the West Bank.
Tunneling became easier in 2005 when Israel pulled its soldiers and settlers out of Gaza, and when Hamas won power in a 2006 election.