(JNS) Hamas's Oct. 7 slaughter was "just a rehearsal," the Islamist group's leader in Gaza Yahya Sinwar threatened on Thursday, in his first public statement since the terrorist organization massacred more than a thousand people in Israel.

"The leaders of the occupation [Israel] should know, Oct. 7 was just a rehearsal," stated Sinwar, according to the Maariv newspaper.

On Monday, Israeli media reported that Sinwar paid a visit to several of the hostages held in an underground tunnel in the Strip. One of the hostages released over the weekend said the terror mastermind spoke to them in Hebrew without an accent.

As Israel and Hamas agreed to extend their ceasefire-for-hostages agreement on Monday, Egypt reportedly put heavy pressure on Sinwar.

"Twice during the ceasefire the parties got into a crisis when Yahya Sinwar tried to violate the agreements, the first time last Saturday night," said an Egyptian source with access to official circles in Cairo.

"Egyptian intelligence officers arrived at the Rafah Crossing [to Gaza] and conveyed to Sinwar extremely difficult messages and threats peppered with juicy curses. A short hour later … the Israeli hostages were released," the source added.

On Oct. 14, Israel Defense Forces International Spokesperson Lt. Col. Richard Hecht told journalists that Sinwar and his entire command team "are in our sights."

"Yahya Sinwar is the face of evil. He is the mastermind behind this, like [Osama] bin Laden was. He built his career on murdering Palestinians when he understood they were collaborators. That's how he became known as the butcher of Khan Yunis [in southern Gaza]," said Hecht.

Sinwar was convicted on multiple murder counts by an Israeli court and sentenced to five life sentences, which he was supposed to serve until his death, but in October 2011 he was released from prison—having served only 22 years—as part of the Gilad Shalit prisoner exchange.

After his release, Sinwar gained power and popularity within Hamas, becoming its Gaza leader in February 2017 by defeating Ismail Haniyeh in an internal vote.