A Boston man was arraigned Friday on an assault charge after he allegedly wrapped his arms around a woman, lifted her up, and tackled her to the ground near the MBTA’s Park Street Station in an unprovoked attack overnight, authorities say.

A Transit Police officer at the entrance to the train station observed Loudon Fruth, 27, around 12:40 a.m. apparently instigating an argument with a group of individuals before the incident, Transit Police said in a statement.

“Fruth landed on top of the victim causing her impact to be more substantial,’’ according to the statement. “Fruth then stood up and began to chase after others in the group. The officer intercepted Fruth and placed him into custody.’’