Four people are dead and three others injured following two separate crashes on highways north and south of Calgary over the weekend.

The first crash occurred at about 3:15 p.m. on Sunday on Highway 22 just north Cremona.

Police say that a silver minivan crossed the centre line and into oncoming traffic.

"There were three persons inside a silver minivan that was driving southbound and there was one person inside a northbound tan motorhome," said RCMP Cpl. Warren Wright. "The silver minivan crossed centre into the path of the northbound motorhome (resulting in) a head-on collision."

Two occupants of the minivan, a 63-year-old man and an 88-year-old man, were pronounced dead at the scene. An 84-year-old woman, also a passenger in the minivan, was cut out of the wreckage and taken to hospital by STARS.

All of the victims were from Calgary.

The driver of the motorhome, a 65-year-old man from Red Deer, was the sole occupant of that vehicle. He was treated at the scene by EMS and released.

Highway 22 was detoured for several hours following the crash, fully reopening at 9 p.m.

The investigation into the crash continues.

Less than an hour later, police were called to another crash south of Calgary.

Fort Macleod RCMP was called to a two-vehicle crash on Highway 3, about seven kilometres east of the community.

Police say a Honda Accord sedan was next to a Ford Explorer SUV when it drifted over the lane divider, sideswiping the larger vehicle.

When emergency crews got to the scene, they found three people were involved in the crash.

A 52-year-old male passenger of the SUV was dead at the scene while the 55-year-old man driving the vehicle was transported to hospital with non-life-threatening injuries.

The 18-year-old man driving the Honda was also taken to hospital with non-life-threatening injuries.

RCMP are continuing to investigate and say that charges are being considered.

In the third crash, approximately an hour later at 5:30 p.m., Redcliff RCMP were called to another crash on Highway 3 at Range Road 120.

Police say a westbound SUV was turning left onto the highway when it was struck by a motorcycle.

The motorcyclist, identified as a 44-year-old man from Cypress County, was transported to Medicine Hat Hospital.

He later died of his injuries.

Police are continuing their investigation and no charges have been laid so far.