A Danish nightclub has been accused of discrimination over its language requirements for entry by asylum seekers, prompting fears more establishments could follow suit amid a spate of reports of sexual harassment.

The Buddy Holly nightclub in the southern town of Sonderborg has made headlines after requiring customers to speak either Danish, English or German after women in several Danish towns hosting refugees complained of being harassed by asylum seekers. Amnesty International in Denmark branded the measure discriminatory. "Of course, you can communicate with people if something security-related happens, even if they cannot speak Danish," spokesman Claus Juul told broadcaster TV 2.

Club owner Tom Holden said the club has been implementing the policy since 1997 – long before Europe's worst migrant crisis since World War II. The idea then, he said, was to stop groups of people who arrive in the town's harbor from Eastern Europe and Russia from entering the bar. Buddy Holly regulars voiced outrage at the language requirement. "To us it looked like pure racism," 19-year-old customer Soren Verdoner told regional daily Jydske Vestkysten, referring to two Syrians who were turned away despite having valid IDs. "We often find that there are small groups of Syrians on the street outside, freezing."

The migrant crisis, which last year saw over 1 million people reach Europe's shores, has sharply polarized public opinion in many European Union states. While many people take a liberal stance on resettling refugees, others favor imposing greater restrictions.