(CNN) Police are questioning two people after a group of men in mariachi outfits opened fire at a Mexico City restaurant, killing five people, an official with the city's Secretary of Public Security Office told CNN on Sunday.

More arrests are expected as the investigation continues, the official said. The motive for the shooting is not known.

Dozens of mariachi bands were serenading couples and families Friday in the city's iconic Plaza Garibaldi when five men disguised as musicians unleashed a hail of gunfire.

Five people were killed and several others were wounded, the city's prosecutor's office said.

Police found three people dead, and two others were taken to hospitals where they later died. The victims were identified as three men and two women whose ages ranged from 22 to 46, officials said.

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