There have been a number of casualties in a shooting incident in the US city of Indianapolis, police say.
Witnesses heard several gunshots at a FedEx facility and one said he saw a man firing an automatic weapon.
Some reports suggested five people had been killed and many more injured, but there is no confirmation.
The gunman, said to have been acting alone, is reported to have killed himself. Authorities said there was no further threat to public safety.
Flights from the nearby international airport are not affected.
"As officers arrived, they came into contact with an active shooting incident," city police spokeswoman Genae Cook said.
"Preliminary information at this time is that the shooter has taken his own life. We don't feel like there is an active threat to the community at this time."
A FedEx statement said the company was aware of the shooting and cooperating with the authorities.
"Safety is our top priority, and our thoughts are with all those who are affected," it said.