An article in Monday’s Hurriyet Daily News pinpoints an unassuming tea house called “Islam,” in the eastern Adiyaman province, as a pivotal location in the Islamic State’s assault on Turkey.

Young people were radicalized and recruited to ISIS in this tea house for years, as the terror organization gathered strength for its current wave of attacks. Many elements of the tea house saga will be familiar to those who have studied ISIS recruiting efforts in both the Middle East and Western world.

One distinctive feature of ISIS recruiting stories is the way radicalized young people drift away from their families. In Turkey, those alienated youths were often slipping across the border to matriculate at Islamic State terrorist training camps in Syria.

“Many families lost contact with their children for months at a time while they trained at ISIL camps in Syria before returning to Turkey, with some having married foreign women that are also members of ISIL in the meantime,” reports Hurriyet. “Many families reported their children to police, fearing that they might be involved in terrorism, only for the police to take no action.”

One Turkish recruit, Omer Deniz Dundar, was said to change his clothing and lifestyle after encountering Islamic State ideology at the tea house, informing his father that “his family did not understand true Islam, which he said was being practiced in Syria under ISIL rule.”

When Omer and his twin brother Mahmut disappeared into those Syrian ISIS training camps, their father Mehmet actually went to Syria and searched every camp until he found them, only to be driven away by an ISIS commander who threatened him with execution. Despite their father’s amazing effort to rescue them, the brothers are believed to remain loyal to the Islamic State and are currently being sought by the authorities in Turkey, where it is feared they are preparing for a terrorist operation.

Other deadly graduates of the tea house include suicide bombers Orhan Gonder, Seyh Abdurrahman Alagoz, and the owner of the establishment, Seyh’s brother Yunus Emre Alagoz, who was one of the suicide bombers behind the attack on a peace rally in Ankara that killed over 100 people.

The tea house is a source of great controversy in Turkey, where opposition leaders charge that the Erdogan government’s failure to move against the well-known center of ISIS recruiting was either an act of staggering incompetence or a means of tacitly supporting the Islamic State.

“We are not talking about failure here, but about intent. People we identified months ago are now killing our young. There is only one explanation: [the government] not seeing ISIS as a terrorist organization,” charged opposition lawmaker Veli Agbaba, quoted by the Daily Beast a few days after the Ankara bombing in an article that referred to the cafe as “Turkey’s ISIS tea house of death.”

“I think the government should be held accountable in its ineptness and negligence,” Turkish journalist July Basaran wrote after a tea house radical perpetrated a suicide bombing in Suruc. “Because I find it highly unlikely that these bombers whose names and families were written about by the press several times, were not being watched by the government and came to Ankara from Gaziantep without the National Intelligence Agency knowing about it.”

Among other clues to the sinister nature of the tea house, the Daily Beast article mentions Turkish journalists publishing lists of suspected ISIS militants who frequented the joint, frightened parents who complained about their children becoming radicalized, and eyewitnesses who said the ISIS flag was hanging on the walls. Nevertheless, the tea house kept running, without much attention from the authorities, until it was finally shut down for lacking the necessary operational license.