UPDATE: The Chisago County Sheriff's Office has said the baby has been found safely.
Police in Chisago County have issued an alert for a man who is missing along with his 6-month-old boy.
It comes after the boy's mother was assaulted in a vehicle on I-35, as well as in a gas station bathroom in Wyoming, Minnesota.
The suspect, Ben Tietz, 37, is the non-custodial father of the child, identified as Leo Tietz.
"Child and suspect are believed to still be in the silver Monte Carlo, we know the suspect is armed with large knives, unknown about a firearm," the Chisago County Sheriff's Office said.
The sheriff's office says the Amber Alert process has been started in coordination with the Minnesota BCA.
Tietz and the child are believed to be in a 2002 Silver Chevy Monte Carlo SS.
He is a white man with facial hair, weighing around 250 lbs, wearing a black/grey hoodie.