Peabody Police Lt. William Cook said the accident occurred at approximately 4:21 p.m. near 350 Lowell St. -- between Summit Street and the Centerfield neighborhood.
Two patients were taken to Mass. General Hospital in Boston with "serious bodily injuries" while two others were transported locally to Salem Hospital. Cook said he didn't know the extent of their injuries.
He confirmed that firefighters did use Jaws of Life equipment to free trapped occupants in the vehicles. It was unclear exactly how many people had to be extricated.
Police did not release the names of anyone involved in the accident Tuesday night.
Cook said the department will wait until the state police accident reconstruction team wraps up its report before any charges may be filed.
He did say, however, it looks clear one vehicle was traveling on the wrong side of the road when it smashed head-on into an oncoming vehicle.
As for the traffic, Cook said, the crash couldn't have happened at a worse time of day.
Lowell Street was shut down immediately between Route 128 and Prospect Street and didn't re-open until around 7:15 p.m. Cars were detoured up Prospect Street at one end and onto the highway at the other end.