A bicyclist on vacation in Wells was seriously injured Monday morning when he collided with a vehicle on Atlantic Avenue, police said.

Philip E. Philbin, 52, of Clinton, Massachusetts, was riding on Atlantic Avenue about 7:30 a.m. when police believe he struck a 2011 Land Rover being driven by a 17-year-old.

Although police are conducting a full accident reconstruction, police believe Philbin may have veered into the SUV as they both traveled in the same direction on the roadway, said Wells Police Lt. Jerry Congdon.

Philbin, who was not wearing a helmet, suffered a severe head injury and was flown by helicopter to Portsmouth Regional Hospital.

His condition Monday afternoon was unknown, Congdon said. Police do not believe alcohol or drugs were involved, and the driver stopped immediately after the crash, Congden said.

The driver has not been charged, and police are not releasing his name because of his age, but the investigation into the crash continues, Congden said.