The Israeli army said Tuesday it is channelling water into Gaza's tunnels in a bid to destroy the sprawling underground network used by Hamas militants to launch attacks on Israel.
"It is part of a range of tools deployed by the IDF (Israeli army) to neutralise the threat of Hamas's subterranean network of tunnels," the military said in a statement, confirming media reports.
Dubbed "the Gaza metro" by the Israeli army, there were 1,300 tunnels over 500 kilometres (310 miles) in Gaza at the start of the war in October, according to a study from US military academy West Point.
The military vowed to destroy them in the wake of Hamas's October 7 attack in southern Israel that resulted in the deaths of around 1,140 people, mostly civilians, according to an AFP tally based on official Israeli figures.
Some 250 hostages were also dragged to Gaza during the October 7 attack, of which around 132 are still held captive, including bodies of at least 28 people believed to have been killed.
Since the Hamas attack, Israel has launched a withering air, land and sea offensive in Gaza that has killed at least 26,751 people, mostly women and children, according to the health ministry in the territory.
The Israeli army says that many hostages taken by Hamas have been or continue to be held in the vast network of tunnels.
In December some Israeli media reported the military was leaning towards flooding the tunnels with seawater pumped from the Mediterranean.
But experts had warned the option was dangerous and poses huge risks to Gaza's besieged civilians.
"It will cause severe damage to the already fragile water and sewage infrastructure that's in Gaza," the then UN humanitarian coordinator for Palestinian territories, Lynn Hastings, had warned in December.
"There's even a risk to buildings and roads collapsing because of the increased pressure and infiltration of sea water into Gaza."
On Tuesday the army said it had taken care in a way as to not "damage the area's groundwater".
"The pumping of water was only carried out in tunnel routes and locations that were suitable, matching the method of operation to each case," it said.
"This tool is one of a range of capabilities developed by the IDF and Israel's security establishment in recent years in order to operate against Hamas' underground infrastructure in the Gaza Strip."
The maze of tunnels was initially used to bypass Israel's devastating blockade on the Gaza Strip after Hamas came to power in 2007, allowing the smuggling of people, goods and weaponry in and out of Egypt.
It extended the network after the 2014 Israel-Hamas war and uses them to emerge across Gaza to launch rocket attacks on Israel.