Chicago residents shot by man dressed as postal worker

A man dressed as a U.S. Postal Service worker is being sought by police Friday after opening fire on two Chicago residents during a phony package delivery.

Investigators say the gunman knocked on the door of a home in the city’s South Side neighborhood Thursday afternoon before shooting at the 27-year-old man and 23-year-old woman who opened it up.

As of Friday, “detectives are investigating if this was a real postal worker or someone impersonating one to get access to the victims," Chicago police spokeswoman Jessica Rocco told NBC News.

Police say the man claimed he had a package to deliver to the male victim, who currently is in serious condition after suffering multiple gunshot wounds to the chest, according to WLS. The woman is reported to be in stable condition.

Officials from the U.S. Postal Inspection Service also are assisting in the investigation.