CHICAGO (CBS) — Two men were shot who were quarreling with each other were shot, and one was critically wounded, in the Ashburn community Tuesday evening.

The shooting happened at 4:17 p.m. in the 4000 block of West 79th Street, police said.

The men were in a quarrel with each other when one of them took out a gun and fired shots, police said. It was not immediately clear how both of them ended up getting shot.

One man was shot in the head and was taken to Advocate Christ Medical Center in Oak Lawn in critical condition, police said. The other man suffered a graze wound to the right arm and refused medical attention.

Police late Tuesday had not figured out who was the assailant and who was the victim.

Area One detectives were investigating.