A large number of Tehrik-e-Insaf workers gathered outside the Punjab Assembly on The Mall road and held a demonstration against rigging in Thursday's by-polls to a provincial assembly seat. The party's candidate lost by a few hundred votes to a PML-N candidate.
As the workers and leaders shouted slogans against the PML-N government of Punjab province and the Election Commission, police started a baton-charge.
The policemen also thrashed the workers for resisting arrest.
Those arrested include the president of the party's Punjab chapter, Ejaz Chaudhry, information secretary Andleeb Abbas and the Opposition Leader in Punjab Assembly, Mian Mahmoodur Rashid.
Later, the arrested men and women were released on the order of Chief Minister Shahbaz Sharif.
Tehrik-e-Insaf leaders said the Chief Justice should take note of the police "brutality" and take action against those responsible for the baton charge.
Imran Khan announced his party will launch a drive to protest the Punjab government's "brutal act".
