Police in the U.K. have launched an investigation this week after a video of a Sikh man being brutally attacked in Birmingham emerged online. Officers are determining whether the violence was motivated by religious bias and have urged the victim to come forward, local news sources reported.

The attack appears to have taken place on Birmingham’s Broad Street on March 29, according to the local police department. “It has been suggested the attack was religiously motivated,” a spokesperson for the West Midlands Police said in a statement reported by the Birmingham Mail. “We are currently making inquiries to establish exactly what has happened but at this stage, nobody has come forward to tell us they’ve been assaulted.”

In the video, the Sikh man is seen attempting to cover his face while one man punches and kicks him. At least one other man also attempts to join in the violence as a group of people gather around to watch the assault. The video also appears to show another victim slumped in a doorway a short distance away from the violence.

The disturbing footage went viral after being posted to the “Daily Sikh Updates” Facebook group, where commenters expressed outrage not only about the violence but the lack of response from the gathered bystanders. “I am absolutely disgusted that not one person had the courage to step in and help this man,” one commenter posted. “Why do people stand and watch and let this happen? They're as bad as the attackers,” said another.

The outrage has also taken on an international dimension as a top official of India’s Punjab state condemned the attack as “inhuman, brutal and extremely worrying” on Tuesday, while calling for Indian Prime Minister Narendra Modi to raise the issue with the British government. Sikhs make up approximately 61 percent of Punjab's population, and the state is considered to be the Sikh homeland and the only place in the world where Sikhs make up a majority.

Asians in Britain are more likely than any other ethnic group to be targeted in hate crimes, according to a report by the Institute of Race Relations. In recent years, around 130,000 racially motivated hate crimes were reported annually in England and Wales. Racial violence is largely underreported to authorities, with 55 percent of people not reporting hate crimes to police, attributing their decision to a lack of confidence in an adequate police response or because they deemed the offenses too minor.