ST. PAUL — The discovery of zebra mussels has been confirmed in two lakes in northern Minnesota.

The Minnesota Department of Natural Resources said Hand Lake in Cass County and Upper Cormorant Lake in Becker County, as well as two smaller lakes and a wetland area connected to Upper Cormorant are affected.

A boat coming from Hand Lake had a plant with attached zebra mussels on it, a Cass County water inspector discovered. Divers then found a 1-inch, adult zebra mussel in the lake, the DNR said.

Divers found seven adult zebra mussels in four locations in Upper Cormorant, while Nelson, Middle Cormorant and a downstream wetland will also be listed as infected, the DNR said.

The wetland flows into Big Cormorant Lake where zebra mussels were confirmed in July 2015.