Police in Dhaka have arrested three people, including a university professor, for failing to register information about tenants renting a property who later attacked a cafe in the city, killing 20 people.
Gias Uddin Ahsan, a professor at North South University in Dhaka, his nephew, and the manager of Ahsan's apartment were arrested by Dhaka Metropolitan Police on Saturday (DMP) for failing to comply with rules forcing landlords to register information about their tenants with the police, senior police official Mohammad Masudur Rahman told Reuters.
The men will appear in court on Sunday, he said.
Five militants who were killed by police after they stormed the cafe on July 1 had rented the apartment along with another person in a nearby residential area in May and started living there from June, Rahman said.
"From here they attacked the cafe. There were other militants also who fled after the attack," he said.
"We also found evidence that they kept grenades and other explosives in the apartment. If we had been informed they were living there, then that brutal killing would not have been possible and we could also have arrested the other militants who fled."
Earlier this year, the DMP issued an order to all apartment owners to provide details of their tenants for a database to help police crack down on criminals and militants using rented accommodation as hideouts.
Bangladesh has suffered a series of attacks on liberal bloggers, university teachers and members of religious minorities over the past year.
The government says two domestic militant groups trying to replace secular democracy with Islamic sharia rule are responsible for the violence.
Twenty people - including 18 foreigners - were killed before police stormed the cafe, rescuing 13 hostages and shooting five of the attackers dead.
Interior Minister Asaduzzaman Khan said on Saturday that investigators had identified the masterminds of the attack and that the remaining perpetrators would soon be arrested.
Some of the assailants had attended prestigious schools or universities and had been reported missing, according to the police. One was the son of a politician.