At least eight people were killed after a gunman opened fire at a FedEx facility in Indianapolis late Thursday before also killing himself, police said.
Multiple other people were taken to hospitals with injuries, police said.
The shooting was reported shortly after 11 p.m. and officers arrived to an active shooter incident, Indianapolis Metropolitan Police Department spokeswoman Officer Genae Cook told reporters.
She said the gunman killed himself at the scene. A search found eight bodies, she added.
That number did not include the gunman.
Cook said it was too early to tell if the shooter was an employee of the facility, and that an investigation was underway. A motive was also unclear.
"This is a tragedy," Cook said.
Five people were taken to hospitals, including one person in critical condition, according to police. Two others were treated at the scene, the department said Friday morning in a statement.
But there were also people who went or who were taken to hospitals privately, Cook said, and police were gathering information. No law enforcement officers were hurt, she added.
A FedEx employee told NBC's "TODAY" show that he was sitting outside the building when he heard what he initially thought was a car with engine problems. He soon realized the sound was actually gunfire.
"And when I stand up, I see a man — a hooded figure — I was unable to see his face in detail however," Levi Miller said.
He said the man had a rifle "and he started shouting, and he started firing in random directions." He couldn't tell what the gunman was yelling. "I thought he saw me and so I immediately ducked for cover," Miller said.
Family members were waiting at a nearby Holiday Inn Express hotel early Friday to hear if their loved ones were safe while police chaplains provided support, WTHR photojournalist Joe Fenton tweeted.
In a statement, FedEx said: "We are deeply shocked and saddened by the loss of our team members following the tragic shooting at our FedEx Ground facility in Indianapolis. Our most heartfelt sympathies are with all those affected by this senseless act of violence. The safety of our team members is our top priority, and we are fully cooperating with investigating authorities."
Indianapolis Mayor Joe Hogsett offered prayers to "the families of those whose lives were cut short" and thanked the "city’s first responders for their tireless work overnight."
"Their quick response provided critical aid to those injured in the shooting and brought a measure of calm to an otherwise chaotic scene," he said in a tweet.
Thank you to all of our city’s first responders for their tireless work overnight. Their quick response provided critical aid to those injured in the shooting and brought a measure of calm to an otherwise chaotic scene.
— Mayor Joe Hogsett (@IndyMayorJoe) April 16, 2021
U.S. Rep. André Carson, D-Indiana, whose district includes Indianapolis, said that he was heartbroken by the incident.
"I am heartbroken by the mass shooting at the FedEx facility here in Indianapolis and praying for all affected by this tragedy," he said on Twitter. "I am communicating with local authorities to get all details of the attack and my office stands ready to help everyone affected any way we can."
There have been several mass shootings in the U.S. in recent weeks, including an April 8 shooting at a cabinet company facility in Bryan, Texas, that left one person dead and five others wounded.
Last week, President Joe Biden announced a series of executive actions aimed at tackling what he called a national "epidemic."
"Gun violence in this country is an epidemic and it is an international embarrassment," Biden said at the time.
‘Nobody needs that’: Biden calls to ban assault weapons with high-capacity magazines
His proposals, which are likely to face legal hurdles, are aimed at reducing mass shootings, suicides and domestic violence.
They aim to limit so-called "ghost guns," which can be assembled at home without traceable serial numbers, and make it easier for relatives to flag family members who shouldn't be allowed to buy firearms.
Biden is also seeking to reduce access to stabilizing braces, which can effectively turn a pistol into a more lethal rifle while not being subject to the same regulations that a rifle of similar size would be.
The president will be briefed on the shooting later Friday morning, a White House official told NBC News. The White House chief of staff has been in touch with Indianapolis' mayor, according to the official, who added that the Homeland Security advisor is in contact with law enforcement.
Gun violence in general has skyrocketed in recent years.
The Gun Violence Archive, a nonprofit group that tracks gun violence in the U.S., found that more than 19,000 people died in gun homicides last year. This was the the highest yearly figure in more than two decades, up by nearly 25 percent from 2019.