A bus hit the scene of a road crash near Gaziantep on Saturday morning, killing 16 people and injuring 21.
Hours later a truck hit a crowd of people 250km (150 miles) away in Mardin, also killing 16 people and reportedly hitting emergency workers.
There have been no reports of a connection between the incidents.
Twenty-nine people were injured in the second crash, eight of them seriously, Turkish Health Minister Fahrettin Koca said.
The incident in the town of Derik in Mardin province "occurred after the brakes gave out on a lorry, which hit a crowd", he wrote on Twitter.
The emergency workers had been sent to the scene following a crash involving three vehicles, Anadolu news agency reported.
The first incident on Saturday occurred near the southern town of Nizip in Gaziantep province.
A bus ploughed into rescue crews and reporters who had come to the scene of a crash involving a car that had come off the road.
Three firefighters, two emergency workers and two journalists were among those killed, the governor of Gaziantep said on twitter.
Photos on Turkey's DHA news agency showed the back of an ambulance ripped out and metal debris strewn around it.
Justice Minister Bekir Bozdag has announced an investigation into the crash.
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