The ordeal started near Milwaukee when police said they got a call from someone on board the Greyhound bus. The caller said a man was acting crazy, claimed he had a gun and threatened passengers.
A Greyhound spokesperson said the incident began around 9:50 p.m. The police pursuit started and then crossed into Illinois. State police tried to use stop sticks to pull the bus over and the driver finally complied and the pursuit ended just north of Route 173.
"He was acting crazy. That's what it boils down to. We tried to get him to calm down, there were four or five people telling him to sit back down, but he refused to and that's when I was on the phone with 911 begging for help," said passenger Patrick Dodd.
About 50 people on the bus were removed and eventually brought to Chicago, the Greyhound spokesperson said.
The suspect was taken into custody. No one was injured on board the bus.
I-94 was closed while police investigated before re-opening around 1:15 a.m.
Greyhound bus stopped after incident involving gunman; no injuries reported