Officials said a full investigation would be conducted as soon as conditions were safe.
A resident of the nursing home, Ruza Kajic, said she lived on the third floor of the building and was woken up after hearing a “cracking sound”.
“I looked out the window and saw burning material falling from above. I ran out into the hallway. On the upper floors, there are bed-ridden people,” she told public broadcaster BHRT.
Footage from the scene showed flames erupting from the windows of an upper floor of the nursing home.
The head of the nursing home, Mirsad Bakalović, said he knew everyone who had been caught up in the fire and after everything he had seen during the fire he had decided to resign.
The chairman of Bosnia-Herzegovina’s tripartite presidency, Željko Komšić, offered condolences to the victims’ families and the injured.
According to a spokesperson for the Tuzla University clinical centre, several patients were being treated for carbon monoxide poisoning, three of whom were in intensive care, local media reported.