A full investigation is underway after a fire at Napa Sonoma Grocery Co. in south Reno early Wednesday morning. 

Fire crews responded to the store just after 6:15 a.m. on South Virginia Street near Longley Lane. 

Firefighters say the fire is believed to have started inside an HVAC unit located on the roof - the fire was contained to the unit.

The investigation is ongoing, but fire crews say no foul play is suspected, while the building sustained minimal damage.

No injuries were reported.