Authorities say an off-duty Chicago police officer shot and critically injured his two children before taking his own life.

Chicago police didn't identify the officer involved in Monday's shootings, saying only that he was 31 years old and had been on the force for four years.

Police spokeswoman Monique Bond says officers responded to a "shots fired" call at the home on the city's southwest side at 10:45 a.m.

When they arrived, they were told children were inside so they rushed in. They found the dead officer and the critically injured children.

The 8-year-old girl and 12-year-old boy were taken to Mount Sinai Hospital.

Police say the incident appears related to a domestic dispute involving the children's mother.