(CNN) A cashier at an Illinois convenience store is out of a job after a video showing him questioning customers' citizenship went viral.

Carolina Buitron told CNN affiliate WBBM that she and her cousins were riding their bikes on Tuesday when one bicycle broke down near the Bucky's Convenience Store in Naperville, Illinois.

Her 15-year-old cousin went into the store to buy some chips while they waited for help, she said.

"At first it seemed like he was trying to be friendly," she told WBBM.

Buitron told WBBM that the cashier then questioned the legal status of her two cousins waiting outside.

"He's like, 'oh, are those two girls adopted?' And she's like 'no, they're my cousins, they came from Mexico.' And he asked, 'are they illegal?'"

That part of the incident is not seen in the videos that were posted on Facebook on Tuesday and quickly gained hundreds of thousands of views.

One video begins with the clerk, who has not been identified, saying something to two women about "undocumented people."

He points at his chest and says, "I'm an American."

One of the women then asks, "What is your problem?"

"It's illegal," the clerk said, which led to more arguing.

He then asked the woman, "Are you a citizen?"

"Yes," the woman replied and then repeatedly asked, "What is your problem?"

"

Don't you know the rules?" the clerk asked. "They need to go back to their country."

The argument got more heated and one of the women threatened to call the police.

"ICE will come," the clerk said. "You're in the wrong country."

Dozens of people protested outside of the store on Wednesday.

Buchanan Energy, which owns the Bucky's convenience store, released a statement on Thursday, saying the employee no longer works for the company.

"Within the last few hours, a video was posted on social media displaying a Bucky's associate engaged in a confrontation with a customer. The comments of this associate are not reflective of the core values of Bucky's Convenience Stores. We are aware of the situation and are managing this personnel issue. We take this matter seriously and strive to ensure that all customers are treated with respect.

"After our internal investigation, (the) employee no longer works for the company."

CNN has attempted to identify the cashier to ask him for comment, but his former employer, Buchanan Energy, would not provide his information.

Naperville Mayor Steve Chirico released a statement Wednesday condemning hate in the community.

"I am aware of the video circulating on social media regarding an incident that recently occurred at a gas station in Naperville. Our Naperville Police Department has reviewed the video and is looking into it.

"Let me be abundantly clear: hate has no home here in Naperville. Quite frankly, this type of behavior has no place in society at large. Our city prides itself on being open and inclusive to all. Civility towards each other is an important component of being a global citizen, and I urge everyone in our community to showcase the kindness, compassion, and good decorum that our residents are known for and that our world needs more of."

The Naperville Police Department said they were looking into the incident.

The Naperville Police Department has reviewed the social media video of an incident that occurred at a gas station in Naperville. We will continue to investigate the matter as well as monitor any related activities occurring in Naperville. — NapervillePD (@NapervillePD) July 17, 2019

"The Naperville Police Department has reviewed the social media video of an incident that occurred at a gas station in Naperville. We will continue to investigate the matter as well as monitor any related activities occurring in Naperville."

CNN has reached out to Carolina Buitron and other members of her family, but has not received a response.