A Bangladeshi charity today buried the five Islamist extremists behind July's devastating attack on a Dhaka cafe after their families refused to take the bodies, police said.

The five shot and hacked to death 20 foreign hostages at the Holey Artisan Bakery on July 1 in Dhaka's Gulshan neighbourhood -- an attack claimed by the self-styled Islamic State group.

Military commandos brought the hostage crisis to a bloody end the next morning after they stormed the compound and gunned down the extremists.

The military handed over the bodies of the five attackers and their alleged associate to the police today after no relatives came to claim the bodies for nearly three months.

"We gave the six bodies to Dhaka Metropolitan Police. Since their death no one came to us to take the bodies," military spokesman Colonel Rashidul Hasan was quoted as saying by AFP.