Izmir Governor Yavuz Selim Köşger tweeted that the deaths occurred during a tower extension of a building in the Bornova district, Daily Sabah reported.
A new hotel was being built at the site, reports said. Footage showed a crane dangling from the upper floors of a building.
Emergency crews were conducting search and rescue operations to find survivors and other people injured in the accident.
Izmir Public Prosecutor's office has launched an investigation regarding the incident, Justice Minister Bekir Bozdağ said Friday, as he extended his condolences to the families of those who died at the site.
MNA/PR