CHICAGO (AFP) - A six month old baby who was shot in Chicago while her father was changing her diaper on the seat of a parked minivan has died, police said Tuesday.

The shooting in broad daylight Monday comes as Chicago struggles to stem an epidemic of gang violence that helped push the city's murder rate up 16 per cent to 506 people in 2012. The city has already logged more than 60 murders and 250 shootings so far this year.

"The baby was in the car with her father when someone walked up and shot the baby and the father," Chicago police spokesman Mike Sullivan told AFP.

"Nobody's in custody at this time." The family was no stranger to gun violence before this particular tragedy. Little Jonylah Watkins's 20-year-old mother was shot in the leg last spring while she was pregnant, the Chicago Tribune reported.

"She's very distraught, she's in a lot of pain," family spokesman Pastor Corey Brooks told the paper. "They just got married several weeks ago. This is a tough time." The girl's father was in "serious but stable" condition in hospital, police said.

Brooks and his congregants have offered a US$5,000 (S$6,233) reward for information leading to the killer's capture.

"We're going to take back our neighborhood, we're going to find who did this," he insisted.

President Barack Obama returned to his hometown last month to highlight the "senseless" gun violence ravaging Chicago as he pressed for ambitious gun control measures.

The nation became embroiled in a debate over gun violence in after the massacre of 20 young children and six staff members at a Connecticut elementary school in December but prospects for reform have dimmed.