Batool Mahmud, shown at a June 21 vigil for a slain Muslim teen in Virginia, said of wearing a hijab: “This is identity for a Muslim woman, this is what shows people that you’re Muslim.” (Sharif Hassan/The Washington Post)

The first time Noorulain Iqbal’s aunt urged her not to wear a hijab was about three years ago, when Iqbal began donning the head covering worn by some Muslim women.

“Wait,” her aunt told her, “you’re too young.”

At 23, Iqbal was old enough to make the decision, but her aunt was masking her real worry, Iqbal recalled recently: She fretted that the headscarf would make it harder for her niece to socialize and make friends.

In the wake of the recent slaying of 17-year-old Nabra Hassanen near a Virginia mosque, Iqbal’s aunt and older sister, who do not cover their heads, again beseeched her to stop wearing a hijab, this time for safety.

Tazkiya Smith, left, and Myiesha Jones, right, during a vigil in Reston on June 21 marking the death of Nabra Hassanen near a Virginia mosque. (Sharif Hassan/The Washington Post)

Iqbal has kept her scarf, even as she had changed other routines to be more cautious in public.

“I stopped running outside at night. I am scared to go outside,” said Iqbal, who lives in Fairfax County. But, she added: “It is my identity. I don’t think that I am ever going to take it off. No matter how scared I am.”

Nabra, who lived in Reston, was killed as she and a group of fellow teenagers returned to a Virginia mosque June 18 after a late-night meal during Ramadan.

A man has been charged in the attack, which Fairfax police have said was an incident of road rage as a driver approached the group walking and biking along a street in Herndon about 4 a.m. near the All Dulles Area Muslim Society.

Darwin Martinez Torres is accused of chasing, beating and killing Nabra before dumping her body in a pond near his apartment in Sterling in Loudoun County, police have said.

Fairfax County Police Chief Edwin C. Roessler Jr. and Commonwealth’s Attorney Raymond F. Morrogh have said they will pursue the case as a hate crime if new evidence points in that direction.

But for some Muslim women, the killing of a Muslim girl wearing a hijab and a long dress known as an abaya near a mosque is alarming, no matter the motivation. And the attack has stirred conversations in families about clothing that speaks to faith and identity.

Mourners head to the funeral prayer service for Nabra Hassanen June 21 near Sterling, Va. (Katherine Frey/AP)

Batool Mahmud, 23, a dental hygienist, said her mother is worried about her wearing a hijab while walking. She knows what it feels like to be singled out over the headscarf: In middle school in Delaware a decade ago, she said, a group of teens pulled her hijab from her head.

But “I am not scared,” she said at a vigil in Reston after Nabra’s funeral last month. Hundreds attended, including many like Mahmud who did not personally know Nabra.

“This is identity for a Muslim woman, this is what shows people that you’re Muslim, so if you are taking it off, it is showing them that you’re afraid,” Mahmud said.

Her resolve holds even amid reports on bias incidents targeting Muslims.

FBI statistics show that 257 ­anti-Muslim hate crimes with 307 victims were reported in 2015, the most recent statistics available. More than 2,200 bias incidents against Muslims were ­recorded by the Council on ­American-Islamic Relations in 2016, up 57 percent over 2015.

And there is some suggestion that Muslim women may bear the brunt of that harassment, according to a 2017 survey of about 800 Muslims nationwide by the Institute for Social Policy and Understanding (ISPU), which studies American Muslim communities in the United States.

It found more Muslim women than men said they feared for their safety, with 47 percent of women surveyed compared with 31 percent of the men.

“It is quite likely that because many Muslim women wear hijab, they are more visible and therefore bear the brunt of Islamophobic incidents,” said Dalia Mogahed, an author of the survey, who also oversees ISPU’s research center in Washington.

Two men were fatally stabbed and one was injured, police said, after they tried to stop Jeremy Joseph Christian from shouting anti-Muslim rants at two Muslim women in Portland, Ore., in May. And a video of a woman harassing a Muslim woman at a Trader Joe’s store in Reston went viral, also in May. “I wish they didn’t let you in the country,” the woman told the victim, who was filming her.

Those attacks have strengthened Wardah Khalid’s commitment to please God by wearing a hijab, she said. More than a dozen other Muslim women recently interviewed in the District, Virginia and Maryland echoed her views.

“I think this is a time to actually assert our Muslimness,” said Khalid, 31, co-founder and president of the Poligon Education Fund, an organization that works to increase Muslim American participation on Capitol Hill. She was at prayers at the same Virginia mosque on the night Nabra was killed, she said.

Khalid also was among hundreds at a memorial last month for the teenager in Dupont Circle, one of several throughout the country held to bring attention to Nabra’s death.

“This is not a time to cower away and back away and fear. If you’re attacked for wearing it, then God will reward you,” she said.

As Muslims — and Muslim women — have a greater presence in the United States, clothing lines, including outlets such as H&M, Dolce & Gabbana, and DKNY, are responding to the demand for scarves and dresses that Muslim women wear. Nike has launched a hijab collection for female athletes.

There were about 2.75 million Muslims in the United States in 2011, according to a Pew Research Center estimate. The number jumped to 3.3 million in 2015, or about 1 percent of the U.S. population, and Pew estimates that it will double by 2050.

Yet with that growth also comes increasing assimilation and women who give up their scarves — not out of fear, but from a sense of feeling more integrated into a larger community.

Bahar Heravy came to study in the United States in 2011. In her home country of Afghanistan, she had to dress in traditional clothing. But she stopped wearing it six months after she arrived.

“It was a big obstacle on my way to integrate into a new society,” the 29-year-old D.C. resident said.

Recent attacks on Muslim women, Heravy said, have given her one more reason not to wear a headscarf: personal security.

“They are brave,” she said, referring to women who wear a hijab.

Iqbal is not fearless, but wary — she’s taking precautions but also saying she remains firm about her decision to wear a headscarf.

At the Reston vigil, 51-year-old Ismael Rivera overheard Iqbal talking and leaned in as she finished.

“I am raised as a Christian,” he said, his voice shaking with emotion. He added, “I love you,” referring broadly to Muslims.

She looked at him and shook her head, saying simply: “It is getting worse.”