Updated

Police say the sound of popping balloons mistaken for gunfire prompted schools around Boston's Fenway Park to go into lockdown.

Boston police say officers responded to a call for shots fired around 2:30 p.m. Thursday near the campus of Simmons University.

The university, as well as nearby Emmanuel College, the Massachusetts College of Art and Design, Boston Latin School and the Winsor School all took precautionary measures, including issuing lockdown and "shelter in place" orders.

But Sgt. John Boyle said it was eventually determined a student activity involving balloon popping was the noise source. The lockdowns were lifted just after 3 p.m.

The Boston Globe reports the purpose of the balloon-popping activity wasn't immediately clear. A Simmons spokesman told the newspaper no such activity was planned on campus.