Police reportedly rounded up eight workers, among them a woman, when they were raising anti-state slogans, according to police.
Around two dozen masked activists including young girls and boys gathered outside the press club and raised anti-state slogans, reported Dawn News.
Police, sporting anti-riot gear, later used batons to disperse and arrest them.
A couple of activists suffered injuries while a policeman also sustained minor injuries on his knee, reported Dawn News.
A male activist in a police mobile van told Dawn that they belonged to Jeay Sindh Qaumi Mahaz-Arisar.