A university offered counselling to students “injured and affected” by a group of classmates who wore small sombrero hats to a tequila-themed birthday party.

The row, which erupted at Bowdoin College, a private liberal arts college in the US state of Maine, is being seen as the latest instance of a new mood of censorious political correctness sweeping university campuses on both sides of the Atlantic.

After photos of party-goers wearing the miniature sombreros, several inches in diameter, appeared on social media, administrators at the college immediately sent out multiple emails notifying students about an “investigation” into a possible “act of ethnic stereotyping”.

The General Assembly of Bowdoin students issued a “statement of solidarity to stand by all students who were affected by the ‘tequila’ party”. The party hosts are facing disciplinary action.

The college has even offered offended students “safe spaces” and counselling to help them deal with the emotional impact of the miniature sombrero party.

The row comes amid a growing debate about freedom of expression and political correctness on university campuses. Critics claim some students are becoming excessively sensitive to perceived slights.

Three months ago students at Oberlin College in Ohio objected to their canteen serving sushi, describing it as “cultural appropriation”. The students at the liberal arts college were widely mocked on social media.

And in November last year, yoga classes at the University of Ottawa in Canada were abruptly cancelled because of complaints that the lessons were an unacceptable appropriation of a non-Western practice.

The Bowdoin student newspaper reports that one of the tequila party’s hosts has been placed on “social probation” until March 2017, and must participate in an “educational program” and “active bystander training”. She has also been told to move out of her room and has been banned from this year’s Spring Gala.

Meanwhile, two members of the college’s student assembly are facing “impeachment proceedings” because they attended the bash.

Student Bill De La Rosa told a meeting of students this weekend that he felt the two should be permanently removed from the student body. “What these students did [is they] tainted the experiences of college students, first year students on this campus,” he said. “They feel trapped to be in this place, that if they transfer they’ll lose their financial aid, and that’s wrong.

“These actions have consequences,” he added. “These are leaders on our campus that were chosen and elected to represent the student body. Those actions did not reflect that last week.”

At other US colleges, students have asked for so-called “trigger warnings” on the front covers of classic works of literature, in case people who have had distressing experiences of sexual violence,