The Indiana State Police said the injuries occurred in Kokomo and rural Howard Country.
"All of the reported injuries are considered minor at this time," the state police said. "Most of the injuries were the result of flying debris. There are no reported deaths."
Kokomo Mayor Greg Goodnight said the storm caused "pretty severe property damage" and downed many trees.
"I am in a residential neighborhood and there is a lot of roof damage, windows out, a roof completely taken off the home, power out," he said. "It is pretty substantial. I have seen damage to about 50 homes so far. We are still looking at the damage."
A temporary state of emergency was declared in Howard County and Kokomo, meaning all roads are closed except for public safety and emergency vehicles.
Power was knocked out across the region, with Duke Energy reporting 29,000 outages and IPL reporting 7,500, said CNN affiliate WISH
Starbucks destroyed in tornado
Photos and video posted online showed a Starbucks in Kokomo flattened by the storm. Jamie Ball tweeted: "@Starbucks absolutely destroyed blocks from my hotel @CourtyardHotels in Kokomo, IN!"
No customers or employees were injured, Starbucks said, according to CNN affiliate WRTV.
Brandon Mobley was working on the roof of a restaurant adjacent to Starbucks when one of the tornadoes struck Wednesday afternoon.
Mobley went inside the restaurant where managers were ushering patrons and staff to the walk-in freezer. Instead of following them into the freezer, he opted to stay in the restaurant dinning area -- not realizing the severity of the weather.
"I had never seen a tornado before except what I saw on TV and in the movies," Mobley told CNN.
He started recording on his phone when he noticed debris flying outside. All of a sudden, the entire Starbucks blew over.
"I knew there were people in there since the parking lot was full," he said. "When the storm passed, I went straight over to what was left of the building."
He called 911 but he knew it would take them some time to arrive to the scene.
When he got to the Starbucks, he heard people in the restrooms. Using the tools he had with him, Mobley and the restaurant manger took the bathroom doors off their hinges and helped rescue the people stuck inside.
"There were about 15 people inside both the bathrooms," Mobley said. "Not a single one of them were injured. They were just shook up and panicked."
Mobley said if it wasn't for the Starbucks manager getting all the people in the restroom they wouldn't have made it since the building had collapsed.
One tornado was reported west of Crawfordville, said meteorologist Dave Tucek. Another was east of Indianapolis.
Indianapolis remained under a tornado warning.
Indiana governor leaves campaign trail
Republican vice presidential candidate and Indiana Gov. Mike Pence left the campaign trail and returned home, arriving Wednesday night in Indianapolis and visiting an emergency operations center.
"So, we're headed home and we're going to be home so long as it takes for us to make sure these communities have the resources and the support they need to put themselves back together after these very violent storms," he told reporters.