(CNN) -- Two bartenders have been arrested in connection with the killing of the grandson of civil rights activist Malcolm X, according to the office of the Mexico City attorney general.

Prosecutor Rodolfo Fernando Rios Garza said the men work at a bar called The Palace Club where Malcolm Shabazz and three people had drinks early Thursday.

An argument ensued when the staff said the bill was $1,200. Shabazz was beaten while another man was threatened and stripped of his belongings, Rios said.

Shabazz, 29, was transported to Balbuena General Hospital, where he died of his injuries later Thursday morning, police spokesman Octavio Campos said Friday. The attorney general's office said his injuries were caused by a blunt object and included brain trauma and several broken bones.

Prosecutors said there was no video of the killing because several cameras had been moved and others appeared to have been turned to face a wall.

Police are looking into the actions of other people that night, the attorney general's office said.

The incident took place at Plaza Garibaldi, a rough but famous patch of Mexico City known for its mariachis.

"To all who knew him, he offered kindness, encouragement and hope for a better tomorrow," the Shabazz family said in a statement Friday. "Although his bright light and boundless potential are gone from this life, we are grateful that he now rests in peace in the arms of his grandparents and the safety of God."

A U.S. State Department spokeswoman was aware that a U.S. citizen had died in Mexico but declined to comment further.

"I was saddened, stunned, shocked, to read about the murder of young Malcolm," former Georgia congresswoman Cynthia McKinney said. The former lawmaker had taken Shabazz under her wing, and he had traveled with her to Libya.

"Many of my closest associates have personal memories of their time with him and of his efforts to reach out to them for help," McKinney said. "He was writing a book."

In 1997, Shabazz -- then 12 years old -- was convicted of the juvenile equivalent of second-degree manslaughter and second-degree arson for setting the fire that killed his grandmother, Betty Shabazz, in June of that year. During his sentencing, a psychologist described him as a chronic fire-starter and a paranoid schizophrenic.

CNN's Elwyn Lopez, Mariano Castillo, Marlena Baldacci, Nick Valencia and Sunny Hostin contributed to this report.