Police are investigating a crash that led to the deaths of two more people in southern Alberta, adding to the concerns of officials in the province.

On Thursday evening, Turner Valley RCMP was called to a crash on Highway 543 east of 128 Street at about 9:09 p.m.

Police say that a pair of motorcyclists was trying to pass vehicles on the highway when they ran into the back end of a flatbed truck.

The victims, a 48-year-old female and 57-year-old male, both from Okotoks, died of their injuries at the scene.

Their deaths are the latest in a string of deadly incidents that have authorities concerned as we head into another weekend of summer driving.

So far, seven people have died this week.

The Turner Valley crash took place just a day after a family of five was involved in a serious crash on Highway 36 near Hanna. The family’s three children, a 16-year-old girl, 11-year-old boy and 11-month-old girl were all killed.

On Wednesday, a 66-year-old woman from Cochrane was killed when her vehicle lost control on Lochend Road and drove into the ditch.

On Tuesday, a 60-year-old man was killed in a rollover on Highway 8 just west of Calgary.

RCMP is continuing to investigate the circumstances of each of the crashes to determine a cause.