Team manager Hani Hamwi, left, and Islamic Relief USA staff members talk to an American Red Cross volunteer in a shelter for flood victims. (Abigail Hauslohner/The Washington Post)

At the end of the day, they moved as a group through the halls of a rural high school, which had been transformed into a shelter. They passed a crowd of locals — including volunteers and people displaced by the record-setting floods — and the words on their blue vests seemed to catch everyone’s eye: “Islamic Relief.”

“Are they Islamic?” one woman whispered to the person next to her. Others simply stared.

And it was true. They were Muslim, and they had come from all over the country to the traditionally red state of North Carolina. Islamic Relief USA has been around for more than two decades, but in a year when Republican presidential nominee Donald Trump has frequently cast Muslims as violent radicals, the charity’s volunteers say they have been thrust into the role of unofficial ambassadors for the real Muslim America.

Plodding in their blue disaster-relief vests through neighborhoods devastated by floods, tornadoes and fires, they frequently encounter people who are “pretty surprised to see Muslims,” said Hani Hamwi, 29, the charity’s disaster response team manager.

The Post's Abigail Hauslohner has spent the past week with Islamic Relief USA in Pembroke, North Carolina which flooded during Hurricane Matthew. She walks through one the relief centers using Facebook Live. (The Washington Post)

“I think there’s an image that gets painted in your head of who Muslims are,” Hamwi said. “An American practicing Islam, it’s good for people to see that, hey, she’s a teacher or she’s a medical student and that they took a break to come down here.”

Hamwi is leading a team of 13 in North Carolina, helping to run the largest shelter in Robeson County, which was hit hard by Hurricane Matthew. Here, in one of the state’s poorest stretches of countryside, the Lumber River and a web of streams snake through forests and fields of cotton, tobacco and sweet potatoes. After the hurricane struck, the floodwaters rose swiftly.

“Two levees in Lumberton burst. It happened real fast. So people didn’t have a chance to gather up their stuff,” said Corbin Eddings, a local State Farm insurance salesman who was volunteering at the shelter.

In the first days of the flood, the high school in neighboring Pembroke held more than 800 people, most of whom arrived by bus after being plucked from rooftops or wading through chest-deep water from wooden homes and trailers.

A sizable portion of the county’s population is Lumbee, part of a Native American tribe that is not federally recognized, and another significant portion of the population is black. Many people get by on public assistance and small home gardens dug behind rusting trailers set along dirt roads that wind through patches of forest. Even before the storm brought the Lumber River to more than 24 feet above flood stage, some families were living without running water or electricity.

The Islamic Relief volunteers arrived Friday. Most were in their 20s, and they were embarking on their first “disaster deployment.” There was a teacher and an occupational therapist, an IT consultant and a handful of recent college graduates. They had gotten the call Thursday and boarded flights from California, Texas, Florida, Oregon and the District.

Islamic Relief member Abdussamad Peera, left, removes his shoes as Abdullah Shawky and Faran Kharal pray in an empty school choir room after a day of entertaining children displaced by floods. (Abigail Hauslohner/The Washington Post)

On Saturday, they went out to survey the damage. They saw a collapsed bridge, washed out train tracks and waterlogged cars that would never run again. They saw piles of dead fish in yards the river had invaded, and they saw people wading waist-deep in a murky brown sea. One man dragged a floating mattress with another person on top.

“It was something you don’t expect to see in America,” said Hanna Jalanbo, 22, who traveled here from Orlando, where she is studying for a master’s degree in social work.

On Sunday, the group sorted cans of food, clothes and other donated supplies and scrubbed the school’s wrestling room so that it could be converted into a day-care center for babies and toddlers.

On Monday, the American Red Cross, which was running the shelter, asked them to care for older children so that overwhelmed parents could seek help from the Federal Emergency Management Agency and venture out to assess the damage.

Nasima Chowdhury, 50, of Dallas, who had worked for decades as a special-education teacher, quickly took charge. And within a few hours, a room full of children ages 6 to 10 were stacking Legos with Lina Asfoor, a 23-year-old occupational therapist from Santa Clara, Calif.; reading with Hasana Abdul-Quadir, 23, an AmeriCorps volunteer who spent the past year working in a D.C. school; and playing with Abdussamad Peera, a 55-year-old Pakistani American IT consultant and father of five from Dallas.

Founded in 1993, Islamic Relief is the largest Muslim charity in America, with about $100 million a year in donations. Most of the money is used for aid operations in and around overseas conflict zones, but the group also responds to domestic disasters with a formal team created five years ago.

This year, the charity has responded to eight disasters, including tornadoes in Oklahoma, wildfires in Washington state, floods in Louisiana and Texas, and water contamination in Flint, Mich. Often, charity workers are dispatched to rural parts of the country, where Trump’s anti-Muslim rhetoric has received enthusiastic support.

“The coolest thing about it, in the age of Trump, is when we go out, everyone sees our branding,” Hamwi said. “So whether someone hates it or loves it, wants us there or doesn’t want us there, they get to see that we’re Muslim. Which is kind of awesome, because we get to represent Muslims in America in a way that a lot of people wouldn’t expect.”

Among the North Carolina team members, three, including Hamwi, are Syrian Americans, as well as Muslims.

“Right now, those are probably the worst things you can be: A Muslim, a male in your 20s and Syrian,” Hamwi said. “Anyone watching the news, until they get to know me and understand what I stand for, I can imagine some might have uncomfortable thoughts.”

Occasionally, the organization encounters hostility. This year, a sheriff in rural Louisiana ordered the group out of his parish when they showed up to do damage assessments on flood-ravaged homes. Last year, the mayor of a small town in Illinois told Islamic Relief workers to leave a flood zone after people complained that they did not want Muslims there.

In North Carolina, the volunteers have encountered mostly gratitude — but also some wariness. Looking at Asfoor’s headscarf, one little boy said, “I heard if you take that off, they’re going to cut your head off.”

Still, the children appeared to be thrilled by the volunteers’ attention. They hung off the legs of Salma Alwani, 25, from Claremont, Calif., and took turns combing Peera’s thick mane of gray hair. On the second day, the parents showed up earlier and left a larger number of children, even as the shelter’s population was rapidly shrinking.

“She had so much fun yesterday,” one mother said as she dropped off a 6-year-old.

A 7-year-old girl with a long ponytail told Chowdhury that she, too, wanted to be a volunteer and wear a blue vest. She pointed to Chowdhury’s sparkling pink headscarf and said she wanted to wear that, too.

Among the other shelter workers — a collection of volunteers from the Red Cross, Southern Baptist Disaster Relief and the local community — any initial wariness appeared to dissipate rapidly. One volunteer sorting donated clothes with Jalanbo asked about her beliefs.

“I’ll get back to you,” Jalanbo said, following strict Islamic Relief policy.

“We are supposed to emphasize that we never proselytize,” said Faran Kharal, 24, an Islamic Relief staffer from Los Angeles.

A group of Army National Guard members stationed at the shelter also made an awkward stab at conversation.

“How long have you been in the country?” a staff sergeant asked Peera.

“Uh, since 1980,” Peera said.

Earlier, the staff sergeant had asked Peera whether he got “a lot of flak from white people,” and Peera acknowledged that he sometimes did. But the sergeant, who had served in Iraq, made clear that he welcomed the Muslim volunteers.

“You guys have done a lot,” said the staff sergeant, who spoke on the condition of anonymity because he did not have authority to speak publicly.

“It’s great y’all are out here. There’s a huge stereotype [about Muslims] in North Carolina.”

On Tuesday night, the volunteers had dinner at On The Border in Fayetteville. As they were walking out, an elderly white couple spotted them. “Thank you for what you’re doing,” the couple called out. It happened in other restaurants, too, in the shelter’s parking lot and when Hamwi visited the local Red Cross headquarters at the Fort Bragg Army base.

Hamwi said he likes being noticed, likes that his bright-blue vest says “Islamic Relief” in big, bold letters.

“I genuinely think that people don’t want to live in fear,” Hamwi said. “Which is why I think so many people are excited to see us.”

Hamwi said he often thinks about a man he met last winter after tornadoes sowed destruction in a small Oklahoma town.

“He had a big belt buckle and cowboy boots, and he came up to us all teary-eyed like he was about to break down.

“He said, ‘I’m sorry.’ And I said, ‘For what?’ And he said, ‘I had the wrong idea about you guys.’ ”