A senior defense official said Friday that Israel was operating on the working assumption that the feared kidnappings of three teenage yeshiva students in the West Bank Thursday overnight was a hostage situation.

The official told Channel 2 that authorities were waiting for better intelligence surrounding the events or for a Palestinian group to take responsibility. A Salafist jihadi organization called Dawlat al Islam issued a claim of responsibility for the incident, but it was not clear whether the claim had any credibility.

Brig. Gen. Motti Almoz, the commander of the IDF Spokesperson’s Unit, said Friday evening that security forces were doing everything possible to locate the youths.

Earlier Friday, US Ambassador in Israel Dan Shapiro was briefed on the fact that one of the three teenagers was a dual Israeli-American citizen.

Israel’s security forces were continuing their large-scale operation Friday to locate the three teenagers, and roadblocks were set up around the West Bank to prevent the possible transfer of the three to the Gaza Strip, Channel 2 reported Friday.

Palestinian prisoners in Israel were celebrating the news of the feared kidnappings, according to Channel 2. Over 100 Palestinian prisoners have been on hunger strike to protest their detention without charge.

No Palestinian organization has yet claimed responsibility. A senior Islamic Jihad official on Friday called on Palestinians to kidnap Israeli citizens, arguing that Israel had proven in the past that it was willing to negotiate the release of Palestinian security prisoners in exchange for the lives of its civilians.

Palestinian Islamists have repeatedly called to kidnap Israelis, including to use them as bargaining chips to extract the release of Palestinian security prisoners.

The Prime Minister’s Office said Friday that, since the beginning of the year, the Shin Bet has foiled 14 attempts to kidnap Israelis.

The PMO also said it held the Palestinian Authority of President Mahmoud Abbas responsible for the well-being of the teenagers, adding that the event was the result of Abbas’s formation of a Fatah-Hamas unity government in April.

Prime Minister Benjamin Netanyahu on Friday called the families of the three teenagers, urging them to stay strong, and telling them the State of Israel would do everything possible for their sons. He promised to keep them updated.

Netanyahu met Friday with Defense Minister Moshe Yaalon, Public Security Minister Yitzhak Aharonovitch, IDF Chief-of-Staff Lt.-Gen. Benny Gantz and the Shin Bet at the Defense Ministry headquarters in Tel Aviv for a security assessment.

The three students were reported missing Thursday night after witnesses said they had been seen hitching rides home at around 10 p.m. from their yeshiva in Gush Etzion.

The IDF spokesperson’s office said they lost contact with the three Thursday overnight.

“Since the morning, we have been engaged in operational activity designed to find [them] and bring them [back],” said Almoz. “Over the past several hours, there has been a very large intelligence effort to try and determine what happened with those youths since they disappeared.”

Facts that might interfere with the ongoing investigation, he said, were being withheld at this time.

A torched car with was found in an undisclosed location in the West Bank, the IDF said, adding that checks were underway to determine the connection, if any.

Earlier Friday, Palestinian media reported a firefight between Israeli military forces and Palestinian gunmen in the South Hebron Hills region. According to a report in the Palestinian Ma’an news agency, large IDF forces raided the village of Yatta in the Hebron region and searched houses there. The military had set up road blocks in the area.