The jihadists who slaughtered 20 hostages at a Dhaka restaurant were members of a homegrown Bangladeshi militant outfit and not followers of the Islamic State group, a senior minister said Sunday.

"They are members of the Jamaeytul Mujahdeen Bangladesh," Home Minister Asaduzzaman Khan told AFP, referring to a group which has been banned in Bangladesh for more than a decade.

"They have no connections with the Islamic State."

Islamic State has claimed responsibility for the killing of the hostages and two police officers during an 11-hour siege that ended on Saturday but the government has consistently denied that international jihadist groups are operating in Bangladesh.

Police have released the names and photos of six of the attackers who were shot at the end of the siege. A seventh was arrested and is being interrogated by Bangladeshi intelligence officers.

Khan said that all of the attackers were well-educated and most came from wealthy families.

"They are all highly educated young men and went to university. No one is from a madrassa," the minister said.

Asked why they would have become Islamist militants, Khan said: "It has become a fashion."