Just beyond a massive strip mall, with its Best Buy and Hobby Lobby, Abdul Baasit, the imam at the Islamic Society of Greater Chattanooga, found himself preaching on Friday about a nightmare.
It was Eid al-Fitr, at the end of Ramadan, normally a time of gift-giving and carnival celebration. But the party that had been planned was canceled: A man who had attended prayer services at the center’s mosque killed four Marines on Thursday. And Mr. Baasit, 48, was trying to help Chattanooga’s Muslim faithful cope with their grief over the deaths, and their fear of reprisal.
“You do not want what is not right to be associated with Islam,” Mr. Baasit, a native of Ghana, said in lilting, heavily accented English. “And yet it is happening.”
The fatal shootings, carried out, the authorities said, by Mohammod Youssuf Abdulazeez, 24, a longtime Chattanooga resident who died later that day, have forced Muslims and non-Muslims all over the Bible Belt to again reflect on the South’s anxieties about homegrown terrorism, immigrants and anti-Muslim sentiment.
Federal officials made clear Friday that they had not discovered any ties between Mr. Abdulazeez and extremist groups like the Islamic State.
Unlike Elton Simpson, who was on the radar of terrorism investigators before opening fire at a Prophet Muhammad cartoon contest in Garland, Tex., two months ago, Mr. Abdulazeez did not appear to leave an obvious online footprint of extremist sympathies.
He may have also strayed beyond the tenets of his faith: In April, he was arrested on a drunken-driving charge, and Islam prohibits the use of alcohol. He was awaiting a trial date at the time of his death.
What is particularly disconcerting for many Muslims here and throughout the South is that Mr. Abdulazeez appears to have been no different from many other young American Muslims trying to make their way in a country and a region that have sometimes struggled with an expanding Islamic presence.
The Muslim population in Tennessee, and throughout the South, is significant, made up of native-born Americans and immigrants from all over the Muslim world. Like Mr. Abdulazeez, who graduated from the University of Tennessee at Chattanooga in 2012 with an engineering degree, many work as engineers — or doctors, store owners or cabdrivers.
Families have clustered by nationality in some cases, but there are heavy concentrations of professionals pushed out of a variety of troubled countries living all over the South, sending their children to public schools and colleges, and pooling their money to build mosques and Islamic centers.
Nashville’s Muslim population, for example, has swelled in recent years with an influx of Kurdish and Somali refugees. The Muslim population in Chattanooga is smaller but well established and diverse, made up of first- and second-generation immigrants and African-Americans, said Daoud Abudiab, president of the Islamic Center of Columbia, Tenn., about 45 miles south of Nashville, who is active in interfaith relations throughout the state.
That growth — especially the arrival of immigrants and refugees — has led to a backlash in some quarters, and Tennessee has become a hotbed of anti-Islam activity. The center that Mr. Abudiab helped to found was burned to the ground in 2008, the debris found etched with swastikas and racist graffiti. Three members of a white supremacist movement known as Christian Identity were given prison sentences.
Opposition to a mosque expansion project in Murfreesboro grew so heated that construction vehicles on the property were set on fire, and the mosque members faced years of legal wrangling over zoning restrictions in local government. Then the Tennessee General Assembly took up legislation in 2011 that sought to outlaw the practice of Shariah, or Islamic law, making it punishable by 15 years in jail.
On Friday, Ossama Bahloul, the imam of the Islamic Center of Murfreesboro, said the attack in Chattanooga “was shocking to everyone” because Mr. Abdulazeez seemed so American, having grown up and gone to school in Tennessee.
He said he was horrified by the shooting. “Four Marines serving the country, to be killed like that,” he said. “It is despicable.”
But Dr. Bahloul also said he was worried about what it could mean for all Muslims in the region. “People become upset, and they react,” he said.
Other Muslim leaders echoed that sentiment, describing Friday Prayer and events that combined the usual holiday fare with warnings about Islamic extremism.
Ihsan Bagby, an associate professor of Islamic studies at the University of Kentucky, said that at his mosque in Lexington on Friday, the person giving the sermon talked about what had happened in Chattanooga and the growing threat of radicalization.
“I’m sure comments like that were made throughout mosques in America,” he said. “Just the shock that there’s a kid who seems to grow up in the shadow of the Muslim community and yet chooses a path of extremism and violence that nobody taught them in the community. It’s a betrayal of the community.”
Mr. Abudiab, head of the Islamic Center in Columbia, said he also found the shooting in Chattanooga shocking. “He seemed to be your average all-American young man with a bright future,” he said of Mr. Abdulazeez. “So that’s where the shock lies.”
Here in Chattanooga, Bassam Issa, president of the Islamic Society of Greater Chattanooga, said that the mosque’s members had had little trouble integrating themselves into the community.
“The fact is that this city has been exemplary,” he said. “We have interfaith relations with a lot of churches. We have great communication with law enforcement.”
The Islamic Society of Greater Chattanooga is about three years old, a handsome, sand-colored building with a dome and a minaret — along with a kindergarten-to-fifth-grade school that is expanding to sixth grade next year, and a mosque and a basketball gym that also serves as a fellowship hall.
Mr. Issa estimated that the mosque, one of three in greater Chattanooga, regularly serves 1,000 to 1,200 people hailing from all over the world — Africa, Pakistan, the Middle East, Bosnia.
At Friday Prayer, some members said they were indeed nervous that the shooting could provoke bad feelings.
Mustapha Coulibaly, 36, a native of Ivory Coast, said that some non-Muslims in Tennessee were still upset about the backlash against the Confederate flag. And now this.
Mr. Coulibaly said he was concerned about retaliation, adding, “We know we have a lot of people not being happy.”
But Mr. Issa, a Palestinian who came to Chattanooga in 1973 and studied, like Mr. Abdulazeez, at the University of Tennessee at Chattanooga, said the shootings on Thursday were an affront to everyone in the area. He spoke of his reaction to the shooting with an emphasis on his membership in the broader community, rather than as a Muslim.
“Honestly, the very first feeling was as a human being, second as a Chattanoogan, third an American — an everyday American,” he said.
“It’s the same feeling that you have,” he said to a reporter. “It’s shocking. I’m still in disbelief about what has happened.”