Nade Conrad's long black hair disappeared under the cover of a lilac hijab.

"I feel different," she said.

Conrad, who is not Muslim, had donned the scarf to show support for a Muslim friend at Normandale Community College in Bloomington.

Such acts of "hijab solidarity" are on the rise.

World Hijab Day, a global event inviting people of all faiths to post pictures of themselves in a hijab on social media, is gathering steam. It was at a World Hijab Day event at Normandale — one of several such events held at Minnesota colleges in early February — that Conrad first tried on a hijab.

Minneapolis Mayor Betsy Hodges has worn a head scarf when meeting with leaders of the city's Somali-American community. And Larycia Hawkins, a professor at a Christian college in Illinois, gained national attention after posting a picture on Facebook of herself wearing a scarf along with comments about Muslims and Christians worshipping the same God. The school suspended her over those remarks and on Sunday, she resigned.

The movement is turning heads at a time when many Muslims in Minnesota and elsewhere feel under siege.

Heightened fears about terrorism have created a climate of fear and anxiety among American Muslims, who say anti-Muslim sentiment is on the rise following terrorist attacks in Paris and California. Women who wear the headscarves are especially vulnerable because the head covering clearly identifies them as Muslim.

But hijab solidarity is drawing plenty of critics, too.

Some Muslims say it amounts to "hijab tourism" and doesn't offer an authentic understanding of the struggle faced by Muslim women who choose to cover their hair. Others argue that it endorses a monolithic view of a faith community whose members don't agree that women should wear head coverings. And some Western feminists struggle with the very idea of covering up.

The Arabic word "hijab" means partition. While it's often used to refer to the head covering, the concept of "hijab" has a broader meaning in Islam. It refers to modest dress and behavior, applying to both men and women.

Amina Sanchez, president of the Muslim Student Association at Normandale, is among those who welcome hijab solidarity acts.

"We want others to understand who we are and what we stand for," she said. "Even though there are a lot of Muslims in Minnesota, there are still misconceptions about why we wear it. We're a peaceful people and we would like to be able to walk down the street and not be afraid," she said.

Terrorist attacks in the United States and abroad have made national security a major campaign issue, with Republican presidential candidate Donald Trump calling for a "total and complete shutdown" of Muslims entering the country, at least temporarily.

Other leaders, however, are trying to counter bias against American Muslims. On Wednesday, Barack Obama made his first visit as president to an American mosque. In Minnesota, community leaders from the worlds of business, politics and education took out a full-page advertisement in the Star Tribune on Feb. 1 calling on fellow Minnesotans to reject anti-Muslim bigotry. And the Minnesota chapter of the Council on American-Islamic Relations recently held a first-ever conference on "Challenging Islamophobia" to discuss ways to deal with an uptick in personal attacks.

William O. Beeman, director of the anthropology department at the University of Minnesota, isn't surprised that people are taking a public stand defending Muslims.

"Any time that it is perceived that people are facing discrimination, there will be sympathetic people who will do their best to show solidarity with them," he said.

He compared the hijab solidarity movement to a young cancer patient who loses his hair after chemotherapy. His friends may shave their heads to show him that he is not alone in his fight.

"That's a very natural human tendency," Beeman said.

Nazma Khan was called "batman" and "ninja" by classmates at her New York City high school because she wore the hijab. Those painful memories as a teenager motivated her to start World Hijab Day three years ago.

"I realized this has to be the result of ignorance," she said. "It's ignorance that makes us hate."

Through Facebook, she invited people to wear a hijab for one day to better understand what it was about. Mothers, children, lawmakers and others have participated in the past, posting photos of their hijab-clad heads along with reflections on what they experienced.

"Inshallah (God-willing), my daughter or niece will not go through what I went through," Khan said. "This time is worse than 9/11. I'm more scared now than before."

Nasra Hassan, 20, a student at Normandale Community College, said she doesn't feel unsafe while wearing a hijab. Most of the people she encounters, she said, are "incredibly sweet, incredibly nice."

But she sometimes finds herself face-to-face with the not-so-Minnesota-nice. One day, while working the cash register at J.C. Penney, she offered to help a customer standing in line. The woman said: "Can you get someone else?"

Hassan shook her head at the memory of that day. "Obviously, it's horrible when it happens. But you can't judge everyone on the basis of a few people's actions," she said.

Many Muslims draw a distinction between people who "dress up" as Muslims to look stylish and those who are donning a hijab to protest discrimination.

"If you are standing in solidarity, then I guess you can wear it," said Halima Muse, 18. "But if you're doing it for fashion, then I don't think it's appropriate."