In response to the renewed cross-border fire from Gaza into southern Israel, the IDF attacked terrorists in Gaza, objectives affiliated with Hamas.
Eyewitnesses identified the men as members of the Islamic Jihad militant group, reports Reuters.
The deaths came amid tensions between Palestinians and Israeli forces following United States President Donald Trump announced he would move the USA embassy in Israel to Jerusalem and recognised the city as Israel's capital.
Smoke was seen rising from the Gaza Strip, where the area where the attack was reported to have taken place.
Residents are reporting hearing multiple explosions and that Iron Dome launched at least two intercept missiles.
In response to this attack, an IDF tank and the IAF targeted Hamas terror posts in the southern Gaza Strip.
Lt. Col. Jonathan Conricus, a military spokesman, told reporters that Israel had used a new set of "tools" developed since a 2014 war with Hamas in order to destroy the tunnel.
Hamas threatened Israel with a "heavy price" for demolishing the tunnel.
Several rockets were fired at Israel from Gaza over the weekend, including one that hit near a home in the city of Sderot and another one that damaged a kindergarten. On October 30, Israel blew up an Islamic Jihad attack tunnel that stretched from Gaza under the border into Israel. The rocket was intercepted by an Iron Dome anti-missile battery.
Israel hit a number of Hamas positions in retaliation, killing two members of the terror group, which is the de-facto ruler of the Palestinian enclave.
Hours after two rockets that were fired by Palestinians landed near Israel's border with Gaza on Monday night, a rocket siren was sounded in the Hof Ashkelon and Lakhish regional councils.