AVONDALE — Thieves are stealing catalytic converters in Avondale, according to a police-issued alert.

The thefts occurred:

at 12:52 a.m. Dec. 4 in the 2900 block of North Gresham Avenue

at 9:15 a.m. Dec. 4 in the 3000 block of North Haussen Court

In an alert, police said witnesses saw two people in a dark-colored Dodge Challenger, possibly with Minnesota license plates, steal the expensive car parts.

Anyone with information about these crimes is encouraged to call detectives at 312-744-8263.