Traffic collision forces Sig Alert for all of CA Highway 121: CHP

(KRON) -- A Sig Alert has been issued in Sonoma County for both directions of California Highway 121, north of CA Highway 37, after a traffic collision with reported injuries, says the California Highway Patrol.

There is no estimated time for the roadway reopening.

It is not yet clear what led to the crash or how many vehicles or people were involved.

Commuters are advised to expect delays and avoid the area by taking alternate routes.

This story will be updated.