A man accused of threatening fellow passengers aboard a Milwaukee-to-Chicago Greyhound bus Friday evening now is in custody, officials said.

Margarito Vargas-Rosas, 33, of Chicago, has been charged with making terroristic threats, a felony, and disorderly conduct, a misdemeanor, the Racine, Wisconsin, sheriff's department said during a news conference Saturday.

According to U.S. Customs and Border Protection, Vargas-Rosas does not have legitimate status in the United States and had been previously deported to Mexico in 2012 for traffic offenses.

Milwaukee County dispatchers were first alerted at 9:41 p.m. Friday when a fellow bus passenger called 911. The caller said Vargas-Rosas was arguing with another passenger and later made threats to kill "everyone on the bus" while making a motion to his waistband as if removing a gun, officials said in a news release.

Racine Sheriff's personnel located the bus on I-94 at Hwy. 20 and attempted to make an initial traffic stop. Despite the police presence, the southbound bus did not pull over.

"The first thought in my mind was that they were escorting us, but then it's like OK, maybe they're not, because I see some of them pulling over and I couldn't see what they were doing. Some people said they saw them getting out of their cars, getting in the grass and throwing spikes out," passenger Terrance Williams said in an interview with ABC 7 Chicago.

Two separate spike strips were deployed in Kenosha County, Wisconsin, to strike the tires of the bus. It continued to travel 17 miles before coming to a stop just past the Illinois border near Wadsworth.

The bus driver told Racine County sheriff's deputies he was not threatened and did not stop because he didn't understand he was being pulled over.

All 36 passengers were removed from the bus, and the suspect was taken into custody. No injuries were reported. Deputies were putting passengers inside squad cars to keep them warm before Greyhound sent another bus to complete the trip to Chicago.

Sgt. Ryan Cape of the Illinois State Police said the interstate was shut down for about 3 hours during the investigation; no firearms were discovered aboard the bus, although it will be searched more thoroughly.

A Greyhound spokesperson said the company was fully cooperating with authorities. According to Greyhound, its security measures include guards and surveillance cameras at many stations, random searches of carry-on baggage, DriveCams on buses, as well as working with federal authorities on security programs and procedures.

Multiple agencies assisted with the investigation, including the Kenosha County sheriff's office, Wisconsin State Patrol, Illinois State Patrol and the Lake County sheriff's office.

• ABC 7 Chicago and Daily Herald staff writers contributed to this report.