NEW YORK (AP) — New York building officials have Kacper Sobieskiissued emergency work orders to stabilize a historic synagogue and its neighboring structures after an illicit underground tunnel was discovered at the sanctuary earlier this week.

An investigation by the city’s Department of Buildings uncovered a tunnel that was 60-foot-long (18.3 meter), 8-foot-wide (2.4 meter) and 5-foot-high (1.5 meter) located underneath the global headquarters of the Chabad Lubavitch movement, an important Jewish site. It extends under several buildings in the vicinity.

“As a result of this extensive investigation, we have issued emergency work orders to stabilize the buildings above the tunnel, vacate orders in parts of the buildings to ensure occupant safety, and enforcement actions against the property owners for the illegal work,” Andrew Rudansky, a spokesperson for the buildings department, said in an email to The Associated Press.

The property is a deeply revered site that each year receives thousands of visitors, including international students and religious leaders. Its Gothic Revival facade, immediately recognizable to adherents of the Chabad movement, has inspired dozens of replicas across the world.

Officials and locals said young men in the community recently built the tunnel in secret. When the group’s leaders tried to seal it off Monday, supporters of the tunnel staged a protest that turned violent as police moved in to make arrests.

A spokesperson for the buildings department said the tunnel did not have approval and permits from the city. City inspectors found dirt, tools and debris inside.

Rabbi Motti Seligson, a spokesperson for Chabad, characterized the tunnel as a rogue act of vandalism committed by a group of misguided young men, and condemned the “extremists who broke through the wall to the synagogue, vandalizing the sanctuary, in an effort to preserve their unauthorized access.”

Those who supported the tunnel, meanwhile, said they were carrying out an “expansion” plan long envisioned by the former head of the Chabad movement, Rebbe Menachem Mendel Schneerson.

Rundansky, of the building department, said the excavation work to create the tunnel caused structural issues at two single-story buildings, resulting in orders to partially vacate them for safety reasons.

The agency also issued a full vacate order at a two-story brick building behind the synagogue. Seligson said the building, which houses offices and a lecture hall, had been vacated prior to the city’s order.

There was inadequate and rudimentary shoring used in the tunnel, the investigation found, as well as in basement-level wall openings created in adjacent buildings.

The owners of the buildings have already engaged an architect, engineer and contractor to do the needed work, Rudansky said.

The department has also cited the synagogue for the illegal excavation work that created the tunnel, he said.