In June, UNWRA similarly uncovered a Hamas terror tunnel underneath two of the United Nations agency's schools in Gaza. Because, doing so accomplishes one of two things: either Israel will avoid targeting Hamas operations under such a sensitive target, or children and agency staff will be killed in the cross-fire, providing ammunition for Hamas' PR campaigns against Israel. The tunnel is one of many constructed beneath the Gaza Strip, some of which extend under the border and into Israeli territory.
He did not explain why Israel chose to detonate the tunnel this week, although the presence of fighters inside may have triggered the Israeli action.
A source for the Islamic Jihad militant group said Arafat Abu Marshould, head of the group's armed wing in central Gaza, was killed with a senior associate and two other gunmen, adding that the group's fighters were on "full alert".
"Those who are trying to hurt us are hurting themselves", Prime Minister Benjamin Netanyahu said in a statement.
It destroyed more than 30 tunnels during a 50-day war with militants in Gaza in the summer of 2014, and has found three since then.
Their deaths were announced after Israel "neutralised a terror tunnel leading into southern Israel", military spokesman Jonathan Conricus told journalists.
The demolition was carried out in a controlled explosion that was scheduled ahead of time by the IDF. "Today, we located a tunnel and we destroyed it".
Conricus declined to give further information on the "new technology" but said it was used for the first time in detecting a tunnel.
Hamas is due to hand control of Gaza back to the Palestinian Authority by 1 December under the agreement.
Hamas, which is in the process of reconciling with its rival Palestinian faction of Fatah, accused Israel of attempting to sew discord and "ruin efforts to restore Palestinian unity". A total of 67 Israeli soldiers and six Israeli civilians were killed in the conflict, while 2,251 Palestinians died, according to the United Nations.