Emergency personnel are on the scene of a serious accident on Great Road in the area of the I-495 overpass.
Several people have been injured in a collision between a tractor-trailer and at least one other vehicle, believed to be an Audi, at the intersection of Great Road and I-495 in Littleton.
There were serious multiple injuries resulting from the crash.
According to the Littleton Fire Department, two ambulances were sent to the scene, along with a rescue truck and Engine 4 from the Littleton Fire Department. Advanced life support teams from Townsend and Emerson Hospital and an ambulance from Groton were also dispatched.
A fire department source said the tractor-trailer was from Pitcherville Sand & Gravel, a Billerica firm.
The spokeswoman said the Ayer Fire Department was called to take a victim to the University of Massachusetts Medical Center in Worcester.
She said MedFlight was called, but cloud cover cancelled flights.
She said as of 2 p.m., everyone had been removed from the wreckage. She was unable to confirm how many vehicles were involved.
The accident, reported around 1:40 p.m., has closed Great Road to traffic.