The two victims, a man and a woman both in their 20s, were in their car waiting their turn in the drive-through lane when they honked at the car in front of them.
It was not clear exactly why they honked, but they told police that two men and a woman got out of the SUV in front of them and attacked them.
According to police reports, one of the men attacked both victims in the head and body with a tire iron.
The attackers then drove off.
Police said the victims were taken to the hospital. Their conditions were not immediately released.