A Sikh couple was forced to leave a movie theatre in California for wearing the kirpan, a move which prompted them to seek an apology from the company, AMC Theatres, which runs the cinema complex.
AMC Theatres justified its decision, stating that it had banned weapons of any sort in its 347 theatres across the US and Canada.
"Our 'no weapons' policy prohibits guests from carrying weapons of any kind into our theatres. This national policy is for the safety and security of our guests and staff," it said.
However, undeterred, Manjot Singh, who was on a night out with his wife to watch 'Man of Steel' at AMC cinemas in Emeryville, California, has hired an attorney to sue the firm.
"Sikhs are unfortunately often the target of ignorance and discrimination in the US due to their unique appearance. But just like all other American citizens, Manjot Singh has the right to be treated with dignity and respect in all public accommodations," said Manmeet Singh of the United Sikhs, a Sikh advocacy group based in the US.
"What happened to this couple at the AMC Theatre in Emeryville singling them out because of Manjot's appearance was inexcusable, and we want to make sure that this never happens again to another Sikh patron of the AMC chain," he said in a statement.
Manjot said he was forced to leave the theatre on June 22 after more than 10 humiliating minutes of being made to stand in the lobby.
"At no time did Manjot ever display his kirpan, sheathed or unsheathed," United Sikhs said, adding that a demand had been made to the theatre company to preserve and turn over the surveillance video from the incident, apologise to the couple and change its discriminatory policies targeting Sikhs.
In a statement, AMC Theatres, however, said, "The person in question was approached when our security team noticed the guest was wearing an approximately 5.5-inch unsheathed knife, in clear violation of our rules. We stand by our policy as this matter is about the weapon alone and not at all about religious freedom. The safety and security of all our guests and associates is our duty and responsibility and we take it very seriously."