One of the two persons, who were seen in the video carrying out an attack on a couple with sharp weapons in the capital's Uttara area on Monday night, was arrested from Dhaka's Abdullahpur area yesterday evening.

Alfaz Hossain Shimon, 22, one of the attackers, was arrested around 7:00pm, Hafizur Rahman, officer-in-charge of Uttara West Police Station.

"We are trying to arrest others," he said.

Alfaz is the nephew of Milion Mia, expelled convener of Uttara West Thana unit of Jatiyatabadi Jubo Dal, an official of the police station told The Daily Star.

Dhaka city north unit of Jubo Dal expelled Milon on September 7 last year for "breaching organisational discipline".

Earlier on Monday night, police arrested Mobarak Hossain, 25, and Robi Ray, 22,  in connection with the attack.

They were placed on two-day remand each yesterday.

 According to police, the incident began around 9:00pm when a motorcycle, driving recklessly, hit an auto-rickshaw on Road-9, Sector-7 of Uttara.

 The rickshaw driver protested the incident, and a couple riding another motorcycle also joined in. This led to an altercation, with the riders of the first motorcycle becoming aggressive and issuing threats. They then made a phone call, calling several youths to the scene.

 Shortly after, the youths arrived and attacked the couple with weapons -- the video of the incident went viral on social media.

 Hearing the hue and cry, locals intervened, capturing Mobarak and Robi, beating them, and handing them over to the police.