Kevin Battaglia, the principal at Bedford Park Public School, tweeted this morning that their bus was rear-ended by a New Jersey commuter bus in the Lincoln Tunnel.
A spokeswoman for the Toronto District School Board says none of the 26 students, who were on a graduation trip, have been hurt.
New Jersey Transit says approximately 60 people were on its bus.
Police say 18 people have been injured in the crash, which caused massive traffic delays heading into New York City. The extent of the injuries is not known.
Joe Pentangelo with the Port Authority of New York and New Jersey police says the crash happened at around 9:30 a.m. Wednesday in the centre tube on the New York City side of the tunnel.
The Port Authority says 42 million vehicles a year travel through the tunnel.
Battaglia tweeted he believed the injured people were "maybe on the bus that bumped us."
"Our kids are fine... just eager to get on our way," he wrote.
-with files from The Associated Press