The accident happened as emergency services were attending the scene of another accident, according to video obtained by Reuters, which showed the green semi-trailer crashing into vehicles and pedestrians at high speed.
Turkish Health Minister Fahrettin Koca said eight of the wounded were in critical condition.
According to local reports, first respondents were attending to another accident when the truck lost control and drove into the site.
In another incident in the country, a further 16 people - including emergency workers and journalists - died when a bus crashed into an earlier accident site, regional governor Davut Gul from southeastern province of Gaziantep said. Another 20 people were wounded and received treatment.