Bail for each was set at $1 million. It's unclear whether Alatorre — who was arrested with the help of local police, the FBI, and the Bureau of Alcohol, Tobacco, Firearms and Explosives — had a lawyer to comment on his behalf.

The two men apparently had a disagreement with people inside Tequila KC bar, left, and then returned with handguns, police spokesman Officer Thomas Tomasic had said.

"We think there was something that happened in the bar earlier probably," Tomasic had said. "Unfortunately, they left and decided to take it to another level, came back and started shooting."

Around 40 people were inside the small bar when gunfire erupted around 1:30 a.m., Tomasic had said. The gunfire sent people running for the exits, with the injured leaving trails of blood as they fled. One of the injured was trying to get a ride to the hospital when ambulances arrived.

Police look for 2 men in Kansas bar shooting that killed 4

"It's a pretty small bar, so if you have two guys come in and start shooting, people are just running, running anywhere they can," Tomasic had said.

All four men who were killed were Hispanic, but Tomasic had said authorities did not believe the shooting was racially motivated. The shooting happened in a neighborhood with a large Hispanic population.

Among the dead was a man in his late 50s, another in his mid-30s and two in their mid-20s, police said. Authorities did not immediately release their names.

However, Juan Ramirez, of Kansas City, Kansas, told The Kansas City Star that his 29-year-old nephew was among those killed. He said his nephew left behind a 6-year-old son and a 4-year-old daughter.

"I don't wish this upon anybody," Ramirez said.

Bartender Jose Valdez told the newspaper that he had refused to serve one of the suspects on Saturday night because the man had previously caused problems at the bar. Valdez said the man threw a cup at him and left, but returned later with another man shortly before closing time.

The gunfire created smoke inside the business, Valdez said, and he thought the building was "going to cave in."

Valdez said three of the people killed were regulars whose parents also frequented the neighborhood bar.

"I don't know what to make of it. A sad day for everybody who lost their lives and their families," he said, choking up. "How can you go into a place full of people and just start shooting?"