Gunmen opened fire into a bar and killed seven people, injuring 20 others, Puerto Rico police said Sunday.

A 9-year-old girl and a woman who is eight months pregnant were among those seriously wounded, said police spokeswoman Maria del Pilar Bon.

Police had few details about the shooting that occurred shortly before midnight Saturday in Toa Baja, just west of San Juan, and Bon said they were trying to determine a motive.

The dead, including one woman, had not been identified because their bodies are still at the scene, Bon said.

Authorities say 709 people have been reported killed this year in Puerto, 65 more than during the same period last year.