A violent brawl inside a Texas Whataburger restaurant over an order mix-up has led to the arrests of seven people.

Footage taken inside the San Antonio fast-food joint around 3am last Sunday showed diners arguing before the fist fight began.

Rebecca Noel explained on Facebook that 'part of another table's order was mistakenly brought to' her son Keilin and his friends.

The staff at the Whataburger, on 14600 block of Blanco Road in the north of the city, told the other customers that Noel's group had their food, she claimed.

Noel wrote: 'Moments later, those individuals confronted my son and his friends, and within seconds, the situation escalated far beyond a simple misunderstanding - to a violent assault.'

The video showed a man in light blue jeans and a gray shirt hit another man in the face, leaving him sprawled across a restaurant table.

Moments later, another man in an orange shirt and sneakers was caught unloading punches on a separate person on the ground.

Screams were heard in the background as the fight continued.

'Calm down, calm down, calm down,' one person was heard saying mid-chaos.

'Please calm down.'

The pleas did nothing to stop the violence.

The footage continued with three girls on the establishment's floor, throwing punches and kicks at one another.

Another girl was heard screaming: 'Stop! What the f**k is wrong with y'all?'

Another voice threatened to call the police.

A Whataburger employee, who was off-duty when he jumped into a brawl, was fired, the San Antonio Express-News reported.

Rachel Mosler Wariner, who identified herself as Keilin's aunt, said the 'most sickening part' of the fight was that her nephew 'was just trying to stop a fight between females.'

She commented: 'Being a man who was raised right knows it wasn’t right for that to happen! And they jumped him for trying to help the females.

'I am disgusted and appalled at the animal like behavior of these grown men.

'And the poor kid that got knocked down, hit his head on the table, and then was punch punched [sic] in the face when he tried to stand up is absolutely disgusting!

'They will see their day.'

One of the teenagers involved in the fight suffered a concussion, 40 lacerations, a bite mark, a broken wrist and bruised kidneys, liver and ribs, according to CBS Austin.

San Antonio police arrested seven people after arriving at the scene: Andres Garcia Cardenas, 21; Tyrone Tolliver, 21; Miguel Torres, 57; Meili Torres, 21; Andrew Lopez, 21; Deontae Tolliver, 23 and Veronica Valdez, 53.