A Muslim chaplain has claimed she was the victim of discrimination aboard a US flight after being refused an unopened can of drink by a flight attendant who told her it could be used "as a weapon".

Tahera Ahmad, identified online as head of interfaith engagement at Northwestern University in Chicago, was told she couldn't have an unopened can by the United Airlines attendant, who allegedly said: "I'm sorry, I just can't give you an unopened can, so no Diet Coke for you."

After the man next to her on the flight from Chicago to Washington was served an unopened can of beer, Ms Ahmad inquired again. She said she was told: "We are unauthorised to give unopened cans to people because they may use it as a weapon on the plane."

"So I told her that she was clearly discriminating against me, because she gave the man next to me an unopened can of beer," Ms Ahmad wrote on her Facebook page.