Canadian police are looking into an incident that happened in London, Ontario at a grocery store on Tuesday between two men, CBC reports.

A video posted on Facebook shows a White man wearing a red-T-shirt stopping a darker-skinned man wearing a black hoodie and a backpack from leaving a Sobeys grocery store while calling him an “illegal alien.”

The man being confronted can be seen in the video saying, “I want to leave; stop assaulting me.”

London police George Demopoulos told CBC that the two men had a prior incident together before the video was recorded.

“I couldn’t believe what I was hearing was actually happening in real life,” said Arden Keet, who witnessed the altercation. “I was shocked and surprised that no one else was really that bothered by it, or upset. I was upset how the cashier said, ‘Oh, he was crazy’ (about the man with the backpack). That made me so angry, because if he had a mental illness or something, that doesn’t make it okay for him to be assaulted.”

Demopolous said that the man wearing the backpack declined to press charges.