Authorities say the alleged gunman, William Spengler, laid an ambush for firefighters by setting a blaze and then lying in wait with a rifle or shotgun.
The shooting occurred in Webster, New York, near the shore of Lake Ontario.
“State Police and our State Office of Emergency Management are working in conjunction with local law enforcement to respond to the scene of the horrific shooting that occurred early this morning in Webster as firefighters and police responded to a car fire," Cuomo said.
“All of our thoughts and prayers go to the families and friends of those who were killed in this senseless act of violence."
This latest gun violence comes in the wake of the mass shooting in Connecticut that spurred calls for tigher gun control laws in New York state.
“New York's first responders are true heroes as they time and again selflessly rush toward danger in order to keep our families and communities safe," Cuomo added.
"Volunteer firefighters and police officers were injured and two were taken from us as they once again answered the call of duty. We as the community of New York mourn their loss as now two more families must spend the holidays without their loved ones."
NCPR will have more on this story on Morning Edition and during the 8 O'clock Hour.