United States envoy Jason Greenblatt tweeted, "Extremist statements & provocation vs. Israel by Islamic Jihad significantly harm the people of Gaza & are very unsafe".
Israeli officials have tried to dissuade the terror group, warning of a harsh retaliation by the IDF.
Daoud Shehab, an Islamic Jihad spokesman, called the comments by Netanyahu and Mordechai "a declaration of war". He addressed by name the terror group's leader, Ramadan Shalah, and his deputy, Ziad Nakhaleh, who run the Gaza-based group from Damascus, and said they would be "held responsible" should Islamic Jihad attack Israel.
The group, which may have been holding off retaliating against Israel while the bodies of five PIJ terrorists were missing inside the tunnel, may now be more inclined to launch a surprise attack against Israel since the IDF confirmed last week that they are holding on to those bodies after they found them inside Israeli territory. Israeli officials have accused Hamas of "preparing" for another war with Israel and have threatened retaliatory measures against the Gaza Strip as a whole.
The group said that the tunnel, which had been detected using newly implemented advanced technology and destroyed in a controlled explosion inside Israeli territory, had been under construction "for years".
According to the army, the tunnel had been under surveillance the entire time that it was inside Israeli territory and did not pose a threat to civilians.
But the Al-Hayat report said that Islamic Jihad was undecided on what to do in the wake of the tunnel demolition.
Almost two weeks after the Israeli army blew up a tunnel that ran between the southern Gaza Strip and Israel, killing 12 Palestinian fighters from the Islamic Jihad and Hamas movements, Israel has continued to exchange threats with the groups, saying that it will "respond with force" to any retaliation from Gaza.
Palestinian resistance group Hamas on Monday condemned a United Nations envoy for "holding Palestinian groups accountable for every tension with Israel".
Earlier this month, a senior officer in the IDF's Southern Command warned that the military suspected the terror group may retaliate for the tunnel demolition with attacks on soldiers serving near the border, rocket fire at southern Israeli communities or terror attacks in the West Bank. Hazem Atallah, the Palestinian national police commander, on Wednesday cast doubt on whether the reconciliation agreement can be carried out, warning that his forces cannot guarantee law and order unless Hamas disarms in Gaza. "There are those who still amuse themselves these days by trying to renew attacks against Israel", Netanyahu remarked at the beginning of the weekly cabinet meeting on Sunday.
"I say this to every entity, rogue faction, organization - everyone".