"The government has identified the masterminds of the two attacks, they will be exposed to justice," Home Minister Asaduzzaman Khan told a media briefing but declined to elaborate "in the interest of investigations".
Islamist militants launched a sudden attack on a posh restaurant in Dhaka's upmarket Gulshan diplomatic zone on July 1 killing 22 people, including 19-year-old Indian girl Tarishi Jain among 20 foreigners and two police officers while six suspected militants were gunned down in the commando operation next morning.
Security officials later said they confirmed identities of five of the six suspected slain Islamists.
Six days after the Gulshan cafe attack, militants tried to carry out an assault on the country's biggest Eid congregation in northern Sholakia killing two policemen.
Prime Minister Sheikh Hasina's government has also alleged that fundamentalist Jamaat-e-Islam and its crucial ally the main opposition Bangladesh Nationalist Party of ex-premier Khaleda Zia had patronized the assaults.
The Islamic State had earlier claimed responsibility for the cafe attack but the government said homegrown Jamaatul Mujahideen Bangladesh carried out both the assaults.
IS had also claimed several clandestine target killings on secular and liberal activists, writers and religious minorities including moderate Sufi preachers even as the government had denied presence of any foreign terrorists attributing the assaults to homegrown outfits like JMB.
But in an apparent shift, senior government leaders and police said Bangladeshi militants appeared to be trying to establish IS links or managed to ensure their access to their media outlet to lodge the claims.
"Those who carried out the Gulshan attack were all Bangladeshis but I don't rule out their possible foreign links. However, we don't want to say anything in this regard without any proof," Dhaka police commissioner Asaduzzaman Mia told a separate media briefing at his office.