Investigators yesterday confirmed that three people took part in the attack on Tazia procession in Hussaini Dalan area on October 24.
Earlier, DB police said at least two people were seen in the footage hurling bombs at the procession.
They, however, said there had been no progress in the cases filed for killing publisher Dipon, attacks on publisher Tutul and his two friends Ranadipom Basu and Tarek Rahim and hurling bombs on Tazia procession in the city.
Dhaka Metropolitan Police Detective Branch’s Joint Commissioner Monirul Islam said although they had not been able to make any visible progress they were now sure that three people took part in the attack.
They suspected the involvement of some other people.
He said Masud arrested in ASI Ibrahim Mollah murder case from the city’s Gabtoli area had given confessional statement to the court where he said he had known about the attack.
Monirul said they were yet to arrest the attackers.
Speaking about Dipon murder case he said they did not find any clues from the CCTV footage of Aziz Super Market that could make a major breakthrough.
Monirul said in the past they had solved many cases that had no clue and he hoped that they could unravel the mystery this time too.
On October 31, a gang of criminals attacked Tutul, Rahim and Ranadipam and injured three others.
Another publisher Faisal Arefin Dipon was also attacked almost at the same time. He was hacked to death by unidentified miscreants.
Two cases were filed with Mohammadpur and Shahbagh police stations respectively and DB police are investigating the cases at present.