Updated

There's a bad smell in parts of the Louisville, Kentucky, area but nobody knows where it's coming from.

Media reports say city crews have been trying for nearly a week to pin down the odor that smells like mildew, but so far they've had no luck.

Louisville Metro Air Pollution Control District spokesman Tom Nord says the agency is doing its best to track the odor. Engineering manager Matt King says crews are driving around the city and searching the old-fashion way: with their noses.

Nord says dozens of people have called from different areas of the city that aren't normally associated with bad smells.

He says the agency doesn't think the smell is toxic.