Public safety officials are raising concerns following a deadly weekend on Minnesota roads that saw nearly a dozen fatal crashes, with nearly half involving motorcyclists.

The Minnesota State Patrol says the Friday through Sunday stretch is the deadliest on Minnesota roads since 2016, killing 11 people. Five deaths came from motorcycle crashes and one involved a pedestrian.

State officials said Monday that alcohol and drugs are likely factors in two of the crashes and four are related to speeding.

Preliminary numbers show 146 people have died on Minnesota roads so far this year, up from 137 around the same time in 2017.

Bill Shaffer, motorcycle safety coordinator for the Office of Traffic Safety, is urging motorcyclists to wear protective gear and ride sober.