A Dorchester man was arrested on Saturday after allegedly threatening MBTA transit police officers with a pitbull.

Transit police responded to a call around 8:40 p.m. about an aggressive pitbull onboard an MBTA bus at the Wonderland station, according to a police report. Passengers as well as the bus operator reported to police that they felt unsafe due to the dog's behavior.

Officials approached the dog's owner, 19-year-old Johnny Sadm of Dorchester, to explain the issue and tell him he would have to get off the bus. They would help him with other transportation, police said.

Using "foul language," Sadm said that officers would have to "drag him and his dog off," police said. officials then placed the other passengers on another bus.

As Sadm got off the bus, police reported that he shouted insults at the officers and held his dog in a threatening manner, asking "Do you want to eat them?" referring to the officers, police said. 

Despite being asked to leave the station, Sadm refused and continued his disorderly conduct, police said. When officers attempted to place him under arrest, he "violently resisted," swinging his pitbull at police, officials said. 

Once placed in custody, officials found what they believed to be cocaine on Sadm. He is expected to be arraigned Monday for assault, trespassing, resisting arrest and possession of a controlled substance. 

The dog was released to Sadm's friend. While service animals are allowed on the T at all times, nonservice dogs are allowed "at the discretion of T vehicle operators," according to the MBTA

MBTA policy notes that "dogs must be properly leashed and are not allowed to annoy riders or take up a seat."