Eight people have been shot and killed at a FedEx warehouse in the US city of Indianapolis, police said.
Multiple other people were injured and were taken to hospital, police spokeswoman Genae Cook said. One person is said to be critically ill. Police had previously said the gunman shot and killed himself.
FedEx earlier said it was cooperating with authorities and working to get more information, adding: "We are aware of the tragic shooting at our FedEx Ground facility near the Indianapolis airport. Safety is our top priority, and our thoughts are with all those who are affected."
Live video from news outlets at the scene showed crime scene tape in the car park outside the facility.
A witness who said he works at the facility told WISH-TV that he saw a man with a gun after hearing several gunshots.
Jeremiah Miller said: "I saw a man with a submachine gun of some sort, an automatic rifle, and he was firing in the open."
Another man told WTTV that his niece was sitting in her car in the driver's seat when gunfire erupted.
"She got shot on her left arm," said Parminder Singh. "She's fine, she's in the hospital now."
He added that his niece did not know the shooter.
There have been several mass shootings in America in recent weeks.
Eight people were fatally shot at massage businesses in Atlanta, and 10 died at a supermarket in Boulder, Colorado, last month.
This was at least the third mass shooting this year in Indianapolis.
Five people, including a pregnant woman, were shot and killed in January, and a man was accused of killing three adults and a child before abducting his daughter during at argument at a home in March.
