The head of the local disaster management agency, Wahyu Widhi Wiranata, said eight workers were injured when the three-story structure collapsed in Samarinda, the provincial capital of East Kalimantan.
Rescuers pulled two bodies from the debris and were searching for those missing, Wiranata said. He said the rescuers heard people under the debris shouting for help.
More than 50 people escaped unharmed, he said.
The cause of the collapse was being investigated. The building was to contain shops.
Media reports quoted survivors as saying most of the employees were sleeping inside the building after working overnight to cast the third floor.