(CNN)As dozens of kids played and people picnicked Thursday afternoon at Memorial Park in Uvalde, Texas, gunfire interrupted in what authorities believe was gang-related violence about a mile and a half from the now-shuttered elementary school where 21 people were killed in May by a teenage gunman.
Two people were shot around 5:30 p.m., police said. Two juveniles were taken to hospitals in San Antonio for treatment, the Uvalde Police Department said in a statement; the victims' identities and conditions weren't immediately known.
Four suspects are in custody and being questioned, police said Thursday night. The shooting is believed to be "gang-related," Uvalde Mayor Don McLaughlin told CNN.
When the gunfire erupted, Celeste Ibarra was at the park with her daughter Aubriella, who suffers from PTSD and depression from the May 24 shooting at Robb Elementary School, where she was a third-grader on the day 19 of her schoolmates and two teachers were gunned down, she told CNN.