Provincial police say it's been a deadly June, with 27 deaths on OPP-patrolled roads since the beginning of the month.

Deputy Commissioner Brad Blair says most deaths were caused by poor driver behaviours, such as speeding and impaired or distracted driving.

The deaths came in 23 collisions between June 1st and 21st, with four of the crashes involving double fatalities and one leaving two motorcyclists dead.

Two drivers were charged with impaired driving causing death in separate fatal collisions this month.