According to a recent report, Israel has started pumping seawater underground into Hamas tunnels to flush them out.

The Wall Street Journal reported, citing US officials who were briefed about the Israeli military operations, that the plan to flood the tunnels from the Mediterranean Sea with water has already started.

It was previously reported that the Israeli military had “understood” this decision. Israel Defense Forces had apparently installed five large water pump near the Shati Refugee Camp in northern Gaza. The pumps can flood the tunnels within weeks as they pump thousands of cubic meters of water an hour.

IDF Chief Staff Lt. Gen. Herzi Halevi stated last week that flooding the tunnels is “a good idea”, but he would not comment on specifics.

He said: “We see a lot underground infrastructure in Gaza. We knew there would be lots. It is part of the plan to destroy this underground infrastructure.

We have a variety of ways to deal with tunnels. I won’t go into specifics but there are explosives that can be used to destroy them and other methods to stop Hamas operatives using tunnels to harm soldiers.

“Therefore any means that gives us an edge over the enemy [that uses the tunnels], which deprives them of this asset is a method that we are evaluating.”

Reuters reported Israel’s military was investigating the reports. A spokesperson for the Israeli Defence Ministry declined to comment.

Israel has promised to dismantle Hamas in the wake of the deadly attacks on 7 October, during which Palestinian militants crossed the border from Gaza into the southern part the country and murdered 1,200 people. The militants took hundreds of hostages. Israel responded by launching massive airstrikes and ground assaults on Gaza that have killed over 18,000 Palestinians.

At a Washington press conference on Tuesday, US President Joe Biden did not directly address reports that Israel was pumping seawater through Hamas’ tunnels in Gaza. He made only a comment about the lack of hostages within the targeted areas.

Mr Biden stated: “In regard to the flooding in the tunnels. I am not a liberal. There are (are) claims that there are no hostages in these tunnels. “But I don’t have that as a fact.”

He said: “I know, however, that every civilian death is a tragedy. And Israel has declared its intention, as I have stated, to match words with actions.”

Israel did not disclose when it planned to pump seawater in the tunnels. However, footage of water flowing into the tunnels was released, though it could not be independently verified. According to a previous WSJ article, officials in the US privately voiced concern over the plan.

Israel’s Foreign Ministry claims that at least 1,370 underground tunnels were built between 2007 and 2011. The tunnels are usually between 10-20m below the surface and can reach up to 2 metres in height.

Environmental experts warned that pumping seawater through a system of tunnels underground could have long-lasting effects on the groundwater in Gaza.

The Times of Israel quoted Prof Eilon Adar of the Zuckerberg Institute for Water Research at Ben-Gurion University of the Negev in southern Israel as saying: “The negative impacts on groundwater would last for many generations, depending on the amounts that infiltrate into the subsurface.”