Newborn twins joined at the stomach and legs died on Tuesday in Bangladesh after efforts by a team of surgeons to separate them failed.
The cause of death was given as multiple organ failure.
"They were very rare conjoined twins," said Tahmina Banu, one of the surgeons at Chittagong Medical College Hospital in southeastern Bangladesh.
"We thought the dominant child would survive if we could separate him through surgery. But both died within minutes," Banu told AFP.
The twins, one male and the other's sex not identified, were born on Saturday with four hands, three legs and no developed excretory organs.
Four previous operations in Bangladesh to separate conjoined twins in the past few years have resulted in the deaths of all but two children.
Last August, a four-month-old Bangladeshi girl died hours after marathon surgery by 50 doctors, nurses and technicians to separate her from her twin sister.
In January last year, an Australian charity flew a set of Bangladeshi twins to Sydney because of poor survival rates of separation surgery in the South Asian nation.