Dozens of Harvard Medical School students were joined by faculty and staff in a 15½-minute-long “die-in” in the atrium of the Tosteson Medical Education Center on the school’s Boston campus Wednesday, a school official said.

The demonstration, organized by the students, was part of protests nationwide by medical students Wednesday against the grand jury decisions not to indict two white police officers who killed two unarmed black men, in Ferguson, Mo., and New York City this summer.

Dean for Students Nancy Oriol said the demonstration began shortly before 12:30 p.m. at the center on Longwood Avenue. Oriol and Harvard Medical School Dean Jeffrey Scott Flier spoke to the gathering of about 100 students, Oriol said, following speeches from several students.


Oriol said the students that spoke asked that the administration at Harvard Medical School and Harvard University join them in the protest, and acknowledged that the administrators had done so because they were present at the demonstration.

The students — mostly first- and second-year students — then lay down, covering the floor of the “large” atrium, Oriol said. The students stayed on the floor for 15½ minutes: 4½ to represent the number of hours unarmed Ferguson teenager Michael Brown’s body lay on the ground, and an additional 11 minutes to represent the 11 times Eric Garner, the man killed in New York, told police he could not breathe before he suffocated.

Oriol said the demonstration would have disrupted a lecture, but the lecturer and his audience delayed the start of the talk to join the students.

Kiera Blessing can be reached at kiera.blessing@globe.com.