The incident took place last night, in which around 40 people, who had gathered outside the British Consulate ransacked the office, they added.
According to police, the men were led by one Sajjad Pawne, who runs a local NGO called 'Insaf'.
Pawne and his accomplices had tried to enter the consulate without following the mandatory protocol, police said, adding that Pawne's companions started ransacking the office when he was talking to the cops posted there.
In the melee, three constables were injured following which police resorted to lathicharge and 28 people including Pawne were arrested.
According to police, the provocation behind the attack on the consulate office is not clear and they termed the incident as a "publicity stunt" by Pawne.
Further investigation is on, police said.