Dhaka Medical College Hospital forensic department's Assistant Professor Md Sohel Mahmud led a three-member team to conduct the autopsies at the Combined Military Hospital (CMH) on Sunday.
He told bdnews24.com on Wednesday: "All the deceased had sharp weapon wounds on their heads and necks. Some were hacked on their throats too."
"But most of the foreign hostages were hacked to death. Bullets were found on the bodies of seven of them and they were also hacked in the head and neck."
Responding to a query, Dr Mahmud confirmed that none of the hostages had been killed by the slitting of their throats.
He said, "One of the Italian nationals and one of the Bangladeshi women had died from trauma caused by a blunt force."
On Friday evening, a group of youths carrying guns and explosives seized the Holey Artisan Bakery and O' Kitchen restaurant in Gulshan-2 and took at least 33 people hostages. They killed 20 of them through the night.
Two police officers, who were members of a team that made an early attempt to end the siege, had been killed by explosions set off by the attackers.
Twelve hours later, security forces stormed the outlet on Saturday morning and freed 13 hostages.
The army and government had said that six terrorists were killed and another was captured alive. Police on Monday midnight filed a case naming six dead attackers and several unidentified persons.
Though one of the six has been identified as Holey Artisan Bakery chef Saiful Islam Chowkider, police say he was seen with the group of militants.
Forensic expert Assistant Professor Sohel Mahmud, who had conducted most of the autopsies of the bloggers and writers hacked to death by suspected militants in Dhaka, also led the post-mortems of the cafe attackers.
He said bullets were found on the bodies of the six attackers. Splinters of explosives were also found on three of them.
Mahmud added that blood for viscera test, and tooth and flesh from their bodies for DNA tests were collected on Wednesday.
"We've collected the samples to determine whether these youths had taken something to stimulate excitement before carrying out the attack," he said.