Students were heading to Brooklyn Dreams Charter School when the smoke bomb went off and green smoke filled the bus. The driver stopped the vehicle and opened the windows, but several students complained of teary eyes and had trouble breathing.
Emergency crews treated five children at the scene. All the injured were expected to recover.
"First it lit up in the back, then blew up in the middle where I was sitting," Amari Bhola, 11, told CBS New York. "It just blew up into fumes and it started to stink in the bus a lot. It was really green."
Bhola also told NBC New York that children on the bus were shouting, "Who did this, why would you do this?"