The crash occurred near Akhisar on the Gebze-Orhangazi-Izmir highway in Manisa province, shortly after 11am local time, authorities reported.
The wounded, including the bus driver, were taken to local hospitals. Police detained the bus driver after his discharge, according to reports.
Images from the scene showed blue body bags lined along the roadside next to the overturned bus, which sustained heavy damage to its rear. The tow truck, which appeared to be carrying wooden planks, had also overturned.
Turkiye's Interior Minister, Mustafa Ciftci, referred to the victims as citizens on social media, although authorities have not yet confirmed whether any foreign nationals were among the casualties.
Manisa Governor Vahdettin Ozkan visited the crash site as emergency teams cleared the wreckage. "Work at the scene is currently ongoing under the coordination of the Public Prosecutor's Office," Ozkan said. "We are experiencing, in a painful way, just how vital it is to strictly adhere to traffic rules."