Hamas cells in the West Bank may have initiated their plan to kidnap Israeli citizens after the organization’s exiled leader encouraged the practice of abducting Israelis in a speech last month, a senior defense official said.

“The speech by political chief Khaled Mashaal in Doha [Qatar] last month might have been a signal to Hamas in Hebron to carry out kidnapping operations of Israeli citizens,” the official said Wednesday. “To my knowledge, Hamas [cells in the West Bank] do not [directly] receive this type of order.”

In his May 20 Nakba Day speech, Mashaal read a letter from a Palestinian prisoner and added that he was aware of the hardships of Palestinian inmates in Israeli jails. Then he said that Hamas’s military wing would “provide a response.” He also clarified in the speech that a recent reconciliation deal with Fatah did not signal an end to Hamas’s violent struggle against Israel.

Eyal Yifrach, 19, Gil-ad Shaar, 16 and Naftali Fraenkel, 16, were kidnapped late Thursday night. They were last seen at a hitchhiking post in the Etzion Bloc of settlements south of Jerusalem at around 10:25 p.m.

Israel has publicly blamed Hamas for the abduction, and despite outright denials by the organization, the US has backed Israel’s assertion while Palestinian Authority security forces have been working under the same assumption. PA President Mahmoud Abbas has publicly condemned the kidnapping and called for the safe return of the teenagers.

Over the past six days, the IDF has been conducting a massive security operation in search of the teens throughout the West Bank, specifically targeting Hamas cells. Thus far, Israeli forces have arrested over 250 people, including 50 who were freed as part of the 2011 Gilad Shalit deal that saw thousands of Palestinian prisoners released, among them murder convicts and high-risk security prisoners.

The military has indicated that it will continue the campaign to find the abducted teens and root out terrorists from the West Bank “at full force.”

Early Thursday morning, the Israeli Air Force launched a series of airstrikes in the Gaza Strip, hitting five Hamas positions in the Palestinian enclave. The strikes came in response to a rocket attack on Wednesday that struck a home in a kibbutz in the Sha’ar HaNegev region outside Gaza.

Times of Israel staff contributed to this report.