BROWNSVILLE, Texas — The driver of an SUV that killed eight people when it slammed into a bus stop in Brownsville, Texas, has been charged with manslaughter, police said Monday as investigators tried to determine if the crash was intentional.

Authorities believe driver George Alvarez, 34, of Brownsville, lost control after running a red light Sunday morning, and plowed into a crowd outside a migrant center.

Police Chief Felix Sauceda said Alvarez was charged with eight counts of manslaughter and 10 counts of aggravated assault with a deadly weapon. Officials are awaiting toxicology reports to determine whether Alvarez was intoxicated, Sauceda said, adding that there was no motive that he could discuss. Asked about reports from witnesses that Alvarez was cursing at them, Sauceda said there was nothing to confirm that yet.

The SUV ran a red light, lost control, flipped on its side and struck 18 people, Sauceda said at a news conference Monday morning. Six people died on the scene and 12 people were critically injured, he said. Officials have said the death toll rose later.

Alvarez tried to flee, but was held down by several people on the scene, he said. His bail was set at $3.6 million.

Surveillance video from the Bishop Enrique San Pedro Ozanam Center showed some of the victims sitting on the curb when they were hit at the city bus stop.

“This SUV, a Range Rover, just ran the light that was about 100 feet away and just went through the people who were sitting there in the bus stop,” said shelter director Victor Maldonado, who reviewed the surveillance video.

Some people walking on the sidewalk about 30 feet from the main group were hit too, Maldonado said.

“I think the community as a whole is in mourning for the loss of the souls,” Cameron County Judge Eddie Trevino said Monday. “It’s a terrible tragic event. And regardless, whether it was intentional or accidental, it doesn’t matter. Those now eight individuals that lost their lives and the other 10 that are hospitalized, we’re praying for them and for their families.”

No news was shared indicating whether the driver struck the group of people intentionally as a hate crime.

“I hope it wasn’t,” Trevino said. “The indications are this was just a terrible, tragic accident.”

Victims struck by the vehicle were waiting for the bus to return to downtown Brownsville after spending the night at the Ozanam Center, said Sister Norma Pimentel, executive director of Catholic Charities of the Rio Grande Valley. The shelter is the only overnight shelter in the city and manages the release of thousands of migrants from federal custody.

The victims were all male and several of them were from Venezuela, Sauceda said. The department is working with representatives of Venezuela and other countries.

“Brownsville is a proud, resilient city,” he said. “We will work with our network and supporters to ensure reunification efforts and assistance is made available to all affected.”

The Ozanam center remains at capacity, but there are plans to expand the number of sleeping spaces from 250 to 380 a night.

During the day, migrants are free to seek employment to pay bus fare or plane tickets that cost hundreds of dollars.

“They stand here at seven in the morning,” Victor Maldonado, executive director of the Ozanam shelter, said Monday. “They get picked up to go do odd jobs, paint, cut yards – they get their money and they move on.”

Brownsville, long an epicenter for migration across the U.S.-Mexico border, has become a key location of interest as the U.S. prepares for the end to pandemic-era border restrictions that allowed the quick expulsion of many migrants. The approaching change is sparking concerns about whether the end of immigration limits under Title 42 of a 1944 public health law will mean even more migrants will try to cross the southern border.

Many of those crossing the border are entering through Brownsville just north of the Mexican border town of Matamoros.

Brownsville has seen a marked increase of Venezuelan migrants over the last two weeks for reasons that aren’t yet clear, authorities said. The recent increase in the number of migrants prompted Brownsville commissioners to indefinitely extend a declaration of emergency during a special meeting last week.

Roughly 30,000 migrants, mostly from Venezuela, have entered the U.S. in the region since mid-April. That’s compared with 1,700 migrants Border Patrol agents encountered in the first two weeks of April.