A group of youths attacked the office of Workers Party of Bangladesh in Rajshahi city, damaging all furniture and electronic equipment last night.
Police and witnesses said around 40 people vandalised the office at a two-storied building around 7:15pm.
Some of the attackers pelted with bricks on newsmen who were videotaping moments of the rampage. However, none was injured.
Sub-inspector Shahidul Islam of Boalia Police Station said the vandals were chanting slogans in favour of WP's student wing, Bangladesh Chhatra Moitree.
According to the party insiders, a rivalry between some Moitree and WP leaders might have surfaced from the visit of WP President Rashed Khan Menon, MP to Rajshahi yesterday.
Menon yesterday attended a farmers' rally at Charghat in Rajshahi, demanding dredging of the river Boral.