The Jefferson County Public School's Twitter page confirmed that the crash occurred on Tuesday morning.
The bus was traveling with at least 60 people on board, including carrying choir members, children and flower girls.
"The picture is horrifying, the people who were on the bus are turned to charcoal," Bulgarian Interior Minister Boyko Rashkov said at the crash site.
"You could tell people were in distress, screams were coming from bus," one eyewitness said.
All of those killed were under 10 years of age.
The bus was transporting around 45 band students from Channelview High School who were heading home after a spring break trip to Disney World.
At least six people were injured on Woodhaven Boulevard in Rego Park.