NEWTOWN, PA -- Students at Council Rock North High School report school employees were blocking the doorways with chairs and desks during a 17-minute National School Walkout event Wednesday morning.

A student shared the images on Facebook. She said the teachers were blocking the doors and the school went into a campus lockdown from 9:30 a.m. to 10:30 a.m. Students were told by the district administration if they left the building, they would face discipline. A spokeswoman for Council Rock said the desks were not placed to create a physical blockage but instead were utilized for taking attendance after the event. "We needed a system for student accounting and a space big enough to handle the potential of hundreds of participants. Students who intended to go outside were instructed to use another set of doors altogether and were in NO way impeded or stopped from exiting the building," Susan O'Grady, Council Rock's community relations specialist, said in an email to Patch.

But according to another student, whose family has reported the incident to the local fire department, school staff were blocking the doors. According to that student, teachers physically blocked the doors, and tables were also placed there. The following image from inside the building was shared:

RELATED: No Discipline After All For Council Rock Students Who Walked Out Students still did leave the building, however. (See video here.) Dozens in fact, and they huddled together in the cold for 20 minutes to participate in the national event, which was aimed to raise awareness for stronger gun laws.

The student who shared the above photo said you could only exit the school from one door and to return there was also just one entrance, which is pictured above. Teachers made students write down their names in order to get back in the building, she said.

Students who left were told they would face detention, however, school officials announced after the walkout that they decided to waive any punishment.

A small contingent of parents arrived to watch the walkout from the nearby St. Andrew's church parking lot.

Council Rock students were told by the administration on Tuesday that if they walked out of the building, they would face "disciplinary consequences." The sentiment was a shift in attitude from earlier communication distributed by Superintendent Robert Fraser, who last month said in a letter to parents that Council Rock School District "respects the rights of our students to peacefully assemble, we will permit any student who wishes to participate in this organized event to do so."