The three-storey building collapsed at around 8.40 am.

Authorities have still not revealed the cause of the collapse of the building.

Providing information about the collapse, Istanbul Governor Davut Gül mentioned that two of the injured are in critical condition, announcing that an investigation has been initiated into the incident.

"There is no determined cause for the collapse of the building constructed in 1988. Therefore, we will inform you in the coming hours and days. Our Chief Public Prosecutor is at the scene. Subsequent legal and administrative processes will proceed,” he was quoted as saying by Hurriyet Daily News.

In a written statement, Environment, Urbanization and Climate Change Minister Mehmet Özhaseki confirmed that the building was constructed 36 years ago.

One and a half floors were illegally added after its construction, the minister was quoted as saying by the news portal.

"Initial inspections on-site indicate that the building, constructed in 1988, was built without adhering to architectural and engineering standards, using sea sand in its construction and subsequent interventions that compromised the building's structural integrity," Özhaseki stated.