A senior administration official says the possible plot appears to be focused on New York City and Washington DC.
Authorities believe they have information on possible suspects tied to al Qaeda. The plot is believed to involve three people, including a United States citizen.
Officials are asking people to remain vigilant and go on with their daily lives.
Security, for many people, is a part of daily activity in the buildings they work in and the places they go.
The Mall of America in Minneapolis is one of the largest enclosed shopping centers in the country, visited by 42 million people each year.
Twice a month, the mall, its tenants and its customers participate in a lockdown drill.
The FBI has repeatedly warned that soft targets like this most recent threat, involve crowded malls and they could be a tempting terrorist target.
That is why many places like the Mall of America have their own plans in place.
Federal investigators are taking the threat seriously and are investigating leads.
Because of September 11 ceremonies this weekend here in the Circle City, extra officers will be out in the city.
Indianapolis Public Safety Director Frank Straub says they will keep in close contact with police and take even more precautions if necessary.
The US Secretary of Homeland Security has not issued an elevated or imminent alert at this time. Right now, the National Terrorism Advisory System remains at a heightened level of vigilance.
The Indiana Department of Homeland Security is asking residents about their readiness for emergencies and disasters with a brief online survey, designed to emphasize the need for preparedness during September, which is the 8th Annual National Preparedness Month.
Click here to participate in the survey.