The incident occurred behind Atlandara area around 4.30 AM, catching the sleeping occupants unawares, H J Tapariya, chief fire brigade officer of the Vadodara Municipal Corporation said.
About 14 families were staying in the building.
"Rescue and relief operations are in full swing.However, it is difficult to tell the exact number of people trapped under the debris. A few people, including a minor girl, have been rescued from the site so far," Vadodara mayor Bharat Shah said.
The building was constructed by the Vadodara Development Authority (VUDA), officials said.
The injured have been rushed to SSG Hospital for treatment.
