In the latest Chicago rifle shooting, four people, including a pregnant woman, were gunned down Friday night in the city’s Brighton Park neighborhood.

Over the last year and a half, several dozen people have been shot with rifles in the Brighton Park and nearby Back of the Yards neighborhoods. Police say the weapons are concentrated almost exclusively in these two areas of the city because they’re being circulated by rival Hispanic gangs who are based there and use them “almost exclusively,” the Chicago Tribune reported. In May, two police officers were wounded in a rifle attack in Back of the Yards.

“We are seeing time and again, these weapons are being imported from Tennessee, North Carolina, Indiana,” Alderman Raymond Lopez told the local CBS-TV affiliate. “People are buying them by the trunk loads — $300 a pop for an AK-47, bringing them to our streets.”

Witnesses to the Friday shooting reported hearing heavy gunfire. Police have said they suspect a semiautomatic rifle was used. The exact model isn’t known.

Ida Arvizu, 28, a dental hygienist, was seven months pregnant with a boy she planned to name Reymundo, her family said. The unborn baby died, also. The other victims were 24-year-old Joel Sandoval, the father of the unborn baby and of Arvizu’s 7-year-old daughter. Sandoval’s brother, Miguel, 27, who leaves behind a 1-year-old and a pregnant girlfriend, was also among the dead. A family friend, 21-year-old Michelle Cano, was the final victim.

Cano’s friends gathered near the scene of the shooting on Saturday to memorialize the young man, a line cook who they remembered as funny, popular, and “no gangbanger.”

“Whenever you were with him, it was always smiles, laughs and good vibes,” one of them told the Chicago Tribune. Cano’s 16-year-old cousin and closest friend was fatally shot during a marijuana deal in Back of the Yards in 2013.