A manager of a 24-hour McDonald's in Indianapolis was assaulted Friday by two female customers over Chicken McNuggets, according to reports.

The women climbed through the restaurant's drive-thru window to attack the worker after alleging that they didn't receive all of the Chicken McNuggets from their order, but the manager claimed that they had never ordered more than what was given to them. He even reprinted their receipt to prove it.

"I was like, 'This can't be happening in front of me right now,'" Monique McNeely, a customer in the drive-thru line that witnessed and filmed the incident, told NBC affiliate WISH Saturday. "It was a little bit disturbing at first, but I knew that if I got it on video that I would be able to help the individuals inside the McDonald’s because this is proof that, you know, something horrible was happening to these individuals."

McNeely initially thought she was witnessing a robbery.

The women asked to purchase the item but were instructed by the manager to drive around the building and wait in line. The dispute escalated after the manager told the women to "have a nice day," according to police. The customers, angered by the exchange, proceeded to honk their car's horn and pound on the drive-thru window repeatedly. The women then made their way through the McDonald's drive-thru window to physically attack the manager. They had knocked over a tablet register and a basin full of tea upon entry.

The customers later exited through the window and sped off without receiving their Chicken McNuggets. The manager did not obtain any injuries from the incident. 

Local law enforcement is still investigating the situation. There wasn't surveillance of the altercation available because of the ongoing construction occurring at the McDonald's branch, NBC affiliate WTHR reported Saturday. The manager told WISH that he'd experience a variety of unusual situations working in the fast-food industry, but nothing like this. 

The McDonald's drive-thru has been the subject of other notable incidents. At a McDonald's in Ireland, witnesses were shocked to see, in what was initially believed to be a prank, a male drive-thru customer on Oct. 30 being chased by another man carrying an ax. Video footage emerged in 2013 of an Ohio woman and a McDonald's employee engaging in a verbal altercation over Chicken McNuggets, which led the customer to get out of her car and strike the worker repeatedly.