A provincial police officer has been rushed to hospital after being shot in a standoff in southwestern Ontario.

Ontario Provincial Police (OPP) spokesman Sergeant Pierre Chamberlain said the shooting happened about 10:20 a.m. Monday as the male officer, who has not yet been identified, responded to a call. The officer is part of the force's Huron County detachment.

“I'm not sure how, or what, or why, or where, but there was a shooting. The officer was transported to hospital via air ambulance,” he said.

CTV reports the officer, who has 20 years experience, was in surgery with a head injury at a London, Ontario, hospital. However, Sgt. Chamberlain would not confirm the policeman's injuries or condition.

The shooting occurred as part of a “standoff” with a man, according to Monica Hudon, a spokeswoman for the Special Investigations Unit (SIU). She said the man was wounded and taken to Victoria Hospital in London, which is part of the London Health Sciences Center, for treatment.

The SIU, a provincial agency that examines all death or serious injuries involving police and civilians, has assigned nine investigators to the case.

Helicopter ambulance service Ornge said it airlifted two people to the London Health Sciences Center. One was picked up near the scene of the shootout while the other was transported from Seaforth Community Hospital, where the patient was stabilized.

Ontario Provincial Police Commissioner Julian Fantino was seen getting into a helicopter at a small airport north of Toronto following the shooting. He is expected to address the media Monday afternoon from the OPP's London offices.

Eyewitnesses say 15 to 20 shots were exchanged between the officer and a suspect near the small community of Winthrop, about an hour-and-a-half north of London.

Faith Weber, of nearby Brussels, Ontario, told radio station CKNX she saw the officer and a suspect exchanging gunfire from opposite sides of the road.

“The guy [was] laying in the ditch and the police officer was on the other side of the road in the ditch but he was standing up and they were both shooting back and forth at each other,” said Ms. Weber.

“When I was there, there was probably about five, six shots that already went off, and then we had to move back farther and then there was more shots going off.”

Ms. Weber said more police arrived and the gunfire ended.