A 15-year-old was shot in the leg in North Philadelphia on Sunday night as he was leaving a vigil for a 13-year-old boy who was killed Friday morning, police said.

At least 10 shots were fired just before 7 p.m. Sunday on the 2600 block of North 22nd Street, where dozens of people had gathered to release blue and white balloons in remembrance of a boy who was fatally shot Friday just blocks from his school.

The 15-year-old shot Sunday was struck in the left calf and hospitalized at Temple University Hospital in stable condition, police said. No one was arrested in connection with the shooting, which took place just outside the Cecil B. Moore Recreation Center. Police said it’s unknown if the two shootings are related.

Authorities have not yet identified the 13-year-old, who died after being shot once in the chest on the 3100 block of Judson Street, less than a mile from where the Sunday night shooting took place.

Investigators believe the boy and several others were sitting in a parked car when at least one gunman opened fire into the vehicle. The motive behind the killing is not yet clear.

A spokesperson for the School District of Philadelphia said the 13-year-old was a student on his way to E.W. Rhodes School, which serves students in kindergarten through eighth grades.

The killing and subsequent shooting are the latest examples of how the city’s gun violence epidemic is affecting children and teenagers. There have been 427 homicides this year, the most recorded by early October in decades. The vast majority of those killings were the result of shootings.

The boys were among 167 children who were killed or wounded by gunfire this year, the highest pace since at least 2015.

Staff writer Ellie Rushing contributed to this article.