The leaders and activists of Jatiya Party (JaPa), and Gono Odhikar Parishad clashed in front the JaPa office in Dhaka's Kakrail on Friday evening, August 29.
Both groups chased each other and threw brickbats around 6:15pm, said Atiqul Alam Khandakar, inspector (operations) at the Ramna police station.
"We are on the spot and will provide details later," he said.
Soon after the incident, the army and police personnel rushed to the scene and were trying to bring the situation under control.
Both parties blamed each other for the attack.
Abu Hanif, media coordinator of Gono Odhikar Parishad, said they brought out a procession after a rally demanding a ban on 'allies' of Awami League and when the procession reached Jatiya Party's central office, JaPa activists hurled brickbats towards them.
Mentioning there were 300-400 people in front of the JaPa office, Abu Hanif said they assume Awami League and Juba League men were also there.
"Ten to 15 leaders and activists of our party were injured in the incident and many of them were taken to Dhaka Medical College Hospital," he added.
KR/MSU