Police and the university authorities appealed all on Thursday for information on the incident.
Police filed a case with Shahbagh station accusing unidentified people.
Senior officials have visited the site in front of the gates of Suhrawardy Udyan and TSC as the harassment has sparked widespread protests.
Earlier in the day, the High Court issued a rule on its own ordering the Dhaka University vice chancellor and inspector general of police to report measures taken over the incident.
On Tuesday, a group of youths sexually harassed women in public in front of the TSC and Suhrawardy Udyan gates during the Pahela Baishakh festivities.
Dhaka University unit chief of Bangladesh Chhatra Union Liton Nandi broke his arm while trying to stop the assault.
Baten claimed there were adequate police personnel in the area and they did their job.
“We’ve taken footages from CCTV cameras and been trying to identify those linked to the incident and their motive,” he said.
He said police spoke to the students and others who witnessed the incident.
Acting Proctor Amzad Ali said they watched the footages, too.
“We’ve watched an hour-long footage. No student or any face known on the campus was seen. But we are yet to watch all the footages,” he said.
He also said no incident of planned sexual harassment was seen in the footage he watched.
“The footages could not be seen properly due to lack of light. I’ve seen people going here and there. Some incidents of shoving could be seen but no planned assault was there,” Ali said.
A statement of the university said its committee on prevention of sexual harassment was already at work.
The committee urged the witnesses to provide authoritative information to its Convener Pro-Vice Chancellor Professor Nasreen Ahmad within Apr 23.
Like the acting proctor, the statement termed the incident ‘so-called’.
Ali said they had plans to prevent such incidents.
“But the plans did not work hundred percent,” he added.
Police angry over allegation
Police have come under fire again since the incident of sexual harassment occurred only one and a half months after the killing of writer-blogger Avijit Roy in the same area.
Witnesses said police took no effective step during the incident but charged batons on innocent people.
Allegations have it that police did catch some of the assaulters but freed them later.