(Updated at 2:50 p.m.) Washington-Liberty High School was on lockdown this morning after the school received a call stating that a shooter was inside the building.

ARLnow received more than a dozen tips, some from parents of students, about the incident at 1301 N. Stafford Street. School staff say students have been moved to a safe location; ARLnow hears that several dozen students sheltered in place inside the school.

“We received an anonymous call this morning during arrivals claiming that there was a shooter in the building,” W-L Principal Tony Hall said in a message to staff and families. “While there is no evidence of an immediate threat, we immediately locked the building down and notified the Arlington County Police Department.”

“All students are in a secure location,” Hall added. “Students arriving have been temporarily moved to a safe location offsite while the ACPD conduct their investigation.”

SWAT teams searched the building while other officers directed traffic, including numerous school buses left without a place to go.

“Just prior to 8 a.m., police received the report of a possible active shooter at Washington and Liberty High School,” said police department Ashley Savage. “Arlington Public Schools placed the school on lockdown. Responding officers have not located evidence of a shooting nor any victims. Police are conducting a search of the building.”

Just before 10 a.m., Arlington County police said the “all clear” has been given and that there is “no apparent ongoing threat.”

Roads around the school were closed and sidewalks were full of students after the lockdown. Police asked groups of students milling about near the school to disperse. Students exiting the school were reunited with their parents.

Many students were evacuated to the Buck site across N. Quincy Street from the school and then to a nearby park. A student described confusion among students during the evacuation, though in a video shared with ARLnow students appeared to remain calm.

“There was just one teacher and one substitute handling a crowd of ~1,000 students as we marched to the park,” said Aaron, a W-L student. “After that, students began to disperse, walking/running to the subway, the library, the baseball field, etc. Some students began crying, others were scared, some were glad they could skip school.”

Around 10:15 a.m., Arlington Public Schools announced that school at W-L has been cancelled today:

Police are still investigating the anonymous report of a shooter inside the school this morning. There has been no evidence of an immediate threat. As a safety precaution, W-L is cancelling school for today, October 6. Walkers have been dismissed. Students who drove their cars cannot access their vehicles until the investigation is complete. Bus riders are being picked up and taken home now. Anyone who is a car rider or who needs to be picked up will be taken to Dorothy Hamm Middle School where parents can pick them up beginning at 10:30 a.m. W-L students at the Career Center will be dropped off at their bus stops. An update will be shared with the community when the investigation is complete, and we will provide the status for tomorrow.

Asked about a possible link between the “shooter” phone call and a subsequent shooting at a high school in Arlington, Texas, which injured at least four people, Savage said there’s no evidence of a connection thus far.

“The preliminary investigation has not revealed a link to any other cases, however, this remains an open and active investigation,” Savage told ARLnow.

In a letter to students and parents Wednesday afternoon, Hall said the school will “open on time and resume our normal schedule tomorrow, Oct. 7.”

“There will be additional police presence at school tomorrow,” the principal added.