A senior Israeli government official said Friday that the noose was tightening around the kidnappers of the three teenagers who were abducted last Thursday from a hitchhiking post in the Gush Etzion area in the West Bank, as a large-scale, ongoing IDF operation to locate the trio continued through its eighth day.

Speaking to Channel 10, the official said that, based on security assessments, the teens were still somewhere in the West Bank and that their abductors were unsuccessful in moving them in the direction of Jordan, Gaza, or Sinai.

Troops were concentrated in large numbers in an area close to Hebron on Friday night, with soldiers searching house-to-house and the area was closed off to outside traffic.

Naftali Fraenkel, Gil-ad Shaar and Eyal Yifrach were last seen last Thursday night. Several Palestinian groups have taken responsibility of their abduction but the authenticity of the claims are questionable.

The Israeli government has pointed the finger at Hamas and said it holds the Palestinian Authority responsible for their fate. PA President Mahmoud Abbas on Wednesday criticized the kidnapping, said the youths must be returned, and confirmed ongoing security cooperation with Israel to try to locate them. Hamas has praised the kidnapping without claiming responsibility, and slammed Abbas for siding with Israel.

Prime Minister Benjamin Netanyahu met with the families of the three earlier Friday and updated them on the progress of the search. Fraenkel’s uncle was later quoted saying that all indications were that the three are alive. On Thursday Netanyahu said Israel knew more about their fate than it had done a few days earlier, and Defense Minister Moshe Ya’alon said the operation to find the three was making progress. Also Thursday, an Israeli official named a deported Hamas terror chief, Saleh al-Arouri, as a suspect in orchestrating the kidnapping.

Israeli forces are embarked on a massive campaign to locate the three kidnapped boys while simultaneously destroying parts of the Hamas terror infrastructure in the West Bank.

Over the past week, thousands of Israeli troops have searched hundreds of locations in the West Bank and arrested more than 300 Palestinians, many of them from Hamas, including some who were freed in a 2011 prisoner exchange for Hamas-kidnapped Israeli soldier Gilad Shalit.

Israeli officials have continuously said that the working assumption was that the boys are alive.