A three-alarm fire has damaged businesses in a Carmel strip mall.

The fire that began at a Dunkin' Donuts shop Thursday morning spread to a winemaking shop and threatened other businesses in the suburb just north of Indianapolis.

WTHR-TV reported employees arrived around midnight and first called firefighters two hours later after spotting smoke. Firefighters checked out the building and left, allowing people back into the building, but workers saw more smoke around 4:15 a.m. and called firefighters again.

Local television reports showed flames and thick smoke rising from the fire more than three hours later. Part of the doughnut shop had collapsed. Indianapolis firefighters joined the effort to extinguish the fire.

There were no immediate reports of injuries