Five to six improvised bombs were also exploded during the clash
Two factions of Jatiyatabadi Chhatra Dal, student wing of BNP, locked in a clash in front of patry's Naya Paltan central office.
The clash occurred on Monday noon, demanding cancellation of the expel order of 12 Chhatra Dal leaders.
Aggrieved leaders and activists of the student wing, under the direction of now defunct central committee leaders, staged demonstration in front of the party office around 11:30am.
At one stage of the demonstration, the protesters also cut the electricity connection of the office.
When the situation escalated, members of the divided groups were seen chasing and counter-chasing each other on the streets.
Five to six improvised bombs were exploded during the clash, said eyewitnesses.
“When we came out of the office, bombs were hurled at us from the party office and from an adjacent lane,” told a defunct committee joint secretary, seeking anonymity.
“Basically the bombs were hurled at Al Ashraf Mamun, joint secretary of the defunct committee, as he was approaching his bike parked near the gate. But some of us manage to leave the office before him,” he said, adding that three including Mamun were injured during the bomb blast.
Omar Faruk Munna, joint secretary of the defunct central committee, told reporters: "We were told that senior party leaders will talk to us before announcing the schedule of 7th council. But nobody talked to us.
“We also demand cancellation of the expel order of our leaders."
Earlier on Sunday, Chhatra Dal announced the schedule of its seventh council.
The council will be held on July 15, when voters will cast their ballots to elect leaders of Chhatra Dal's new central committee.
On June 22, BNP expelled 12 Chhatra Dal leaders of the recently dissolved committee for breaching party discipline.
Earlier in the day, the aggrieved leaders of the recently dissolved committee threatened to continue their demonstration, until their demands for either the formation of a new short-term committee or the removal of age-limit are met.