Khaleda Zia's motorcade was the target of the 'ruling party's attack' on Wednesday, said the BNP's acting Secretary General Mirza Fakhrul Islam Alamgir at a press conference at the party headquarters at Naya Paltan.
He announced nationwide demonstrations for Friday at metropolises and district headquarters four hours after the violence.
Clashes erupted between BNP and Awami League supporters outside a special court in Bakhsibazar where Khaleda Zia appeared for the hearing in a graft case.
"The plan was to attack the leader's (Khaleda) motorcade. You've noticed that attack had started five minutes before her motorcade reached there," he said.
He claimed that the 'attack' was unsuccessful due to people's 'spontaneous stand'.
"Later they (attackers) assaulted and left over six hundred people injured."
The government will have to arrest the guilty or else they must take responsibility for any situation, he said.
He alleged the ruling party activists launched an attack on Tuesday night while preparations were underway for Khaleda's Gazipur rally.
The BNP chief started for the court from her Gulshan residence around 11:30am.
Activists of the party and its front organisations, who had gathered at Bakshibazar since morning, took out a march around 12:15pm.
The procession was attacked by Awami League supporters at the Bakshibazar intersection, triggering the clash.
Police intervened after a while, firing in the air and teargas canisters to disperse them.
Khaleda's motorcade went to the court amid the clash. She left for her Gulshan residence around 1:30pm.