Multiple people are dead, with at least 18 taken to hospitals Saturday after a shooting near a shopping mall in El Paso, Texas, law enforcement officials said. One suspect, a man, is in custody, police said.

A second person was also taken into custody by authorities, but it is not immediately known what role, if any, the person played in the shooting, sources familiar with the investigation told NBC News.

El Paso police said the initial calls about the incident came at about 10 a.m. local time. By about 1 p.m. police said there was no imminent threat at that point. Earlier, in several tweets, police urged people to stay away from the area near the Cielo Vista mall due to an "active shooter."

Police said at one point that they were receiving reports of multiple shooters but later said they believe there was only one.

The FBI and the Bureau of Alcohol, Tobacco, Firearms and Explosives responded to the scene to assist the El Paso Police Department.

The police tweeted that the shooting situation was in the area of Hawkins and Gateway East boulevards, which is the location of a Walmart.

In a tweet Saturday afternoon, Walmart said it was "in shock."

"We’re praying for the victims, the community & our associates, as well as the first responders," a statement posted on Twitter read. "We’re working closely with law enforcement & will update as appropriate."

A University Medical Center of El Paso spokesman said multiple victims have been taken to different hospitals. University Medical Center got at least 10 victims with "level one" injuries, which is the most serious level, spokesman Ryan Mielke said.

"Our hearts go out to those who have been injured and the families of those who may have been killed," El Paso Mayor Dee Margo said during an interview with NBC affiliate KTSM in El Paso.

Texas Gov. Greg Abbott said in a statement Saturday that he is headed to El Paso.

“While no words can provide the solace needed for those impacted by this event, I ask that all Texans join Cecilia and me in offering our prayers for the victims and their families,” he said. “The state of Texas will do everything it can to ensure justice is delivered to the perpetrators of this heinous act.”

Rep. Veronica Escobar, D-Texas, was an hour into a town hall meeting at Coronado High School 15 miles from the mall, when she abruptly had to end the event because of the shooting.

“You all, I am so sorry,” she said. “There is an active shooter. We are going to need to clear the event.”

The crowd gasped in response and began to move, according to the congresswoman’s Facebook Live video.

“Oh, it’s at Cielo Vista,” Escobar quickly clarified before apologizing for not being clearer.“We’ve been asked by law enforcement to just send everybody home,” she said.

A reunification site for families of possible victims was set up at a local school.

El Paso Community College said in a tweet that all of its campuses have been evacuated "out of an abundance of caution."

Democratic presidential hopeful Beto O’Rourke of El Paso urged residents in El Paso to "stay safe."

"Truly heartbreaking," he wrote in a tweet. "Please follow all directions of emergency personnel as we continue to get more updates."

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