Thirty-seven Palestinians were arrested by the IDF overnight Sunday, as the West Bank operation to locate kidnapped teenagers Eyal Yifrach, 19, Naftali Fraenkel, 16, and Gil-ad Shaar, 16, entered its eleventh day. The latest round of arrests brings the total number of detainees since the beginning of the operation to some 361, the army said.

Eighty separate locations were searched by Israeli troops in overnight sweeps, and the facilities of seven Hamas-affiliated organizations were shuttered, “specifically in the area north west of Hebron, Beit Awwa (southwest of Hebron) and also in (the northern city of) Jenin,” a military spokeswoman said.

“Despite entering Jenin, Tulkarem, Nablus and al-Arrub, there were no high-intensity clashes, but there were violent disturbances,” a senior military official said. “We have no intention of reducing the number of troops operating in the field. An assessment on the situation will be made in the coming days.”

The official added that the upcoming Ramadan holiday was “not a restriction for our troops. We’ve operated for years during Ramadan, with sympathy and consideration” for the holiday, he said.

Former National Security Adviser Major General (ret.) Giora Eiland (photo credit: flash90)

Former National Security Adviser Major General (ret.) Giora Eiland (photo credit: Flash90)

However, Giora Eiland, a retired general and former National Security Adviser, said the operation would inevitably focus increasingly on intelligence-gathering if the house-to-house and other searches on the ground failed to yield hard evidence of where the kidnap victims are being held. He said the passage of time “does not bode well” for the kidnapped trio, given the logistics and practicalities of keeping captives alive.

Interviewed on Israel Radio, Eiland said it was apparent Israel had no hard evidence of where the three were being held, but apparently did have information on who was responsible for their kidnapping, and enough indications to focus the ongoing search on the Hebron area. In the seven hours between the abduction late on June 12 and the start of the search early on June 13, he said, there would have been ample time for the kidnappers to move their captives elsewhere in the West Bank, to Gaza, Sinai or Jordan, but the Israeli working assessment was clearly that they were still in the Hebron area.

Four Palestinians have been killed in clashes with security forces since the operation began. In a letter delivered on Sunday morning to the Defense and Public Security ministries, nearly a dozen human rights groups condemned the kidnapping of the teens but asserted that the sweeping arrests and travel restrictions imposed by the IDF were unfair to the general Palestinian population, and did not necessarily further the goal of freeing the hostages.

In a telephone conversation with Prime Minister Benjamin Netanyahu over the weekend, UN Secretary Ban Ki-Moon similarly “expressed concern” about the operation, urging restraint while asserting that he would continue to condemn terror.

Yifrach, Fraenkel and Shaar were abducted while hitchhiking in the Etzion bloc south of Jerusalem on June 12. The large-scale operation to find the them has been concentrated primarily around the Hebron area.

Troops have arrested Hamas members — whom Israel has said is responsible for the attack — while closing down many of its West Bank institutions. In the course of the campaign, hundreds of weapons were confiscated, and underground tunnels dug under the homes of many Hebron residents were revealed.

Stuart Winer and AFP contributed to this report.