Tangail Superintendent of Police Sanjit Kumar Roy told a news conference that the four were detained from different areas of the town on Wednesday morning.
The detainees are Touhidur Rahman Ratul, Rakib Alam, Robin Hasan and Kausar Ahmed.
The SP said a group of young men had been harassing women in front of the Capsule Market for a long time.
A member of the group went live on Facebook with his friends on Sunday afternoon while throwing abusive words towards women.
When the video went viral, police detectives detained the suspects, the police officer said.