A gunman has killed four people and is also dead after a "catastrophic" shooting at a medical centre in Oklahoma, police confirmed.
More than 20 police cars and other emergency vehicles are by the Warren Clinic, a medical centre on the Saint Francis Hospital Campus, where the shooting is believed to have taken place.
Police are describing the scene as "catastrophic" with a man carrying two weapons, a long gun and a handgun, having opened fire in the building.
A Tulsa Police spokesperson has now confirmed that five people in total had died and ten people have been injured.
They said police received the call about a gunman at 4.52pm (local time) and arrived at 4.56pm.
Police found the victims on the second floor of the building who were dead along with the suspect who is thought to be aged around 35 to 40.
The gunman is believed to have taken his own life when the police approached the room where his body was found.
One medical worker said he called his wife while escaping telling her: "Don't freak out, I'm alive."
Gannon Gill, a physician assistant, was with a patient when the gunfire broke out.
While the shooter was on their rampage, Mr Gill guided his patient and colleagues out of the building and to the parking garage.
He said he called his wife to reassure her he was okay.
Mr Gill told the New York Times: "There was an initial ‘What was that?’"
He also said one of the men in the parking garage had said they bumped into the shooter.
Mr Gill said: “The shooter told him and his wife to leave and he was not there for him.."
He added: "You see this stuff on television or the news, but you don’t think it's ever going to happen in your workplace.”
And Tulsa Police Cpt. Richard Meulenberg said that there was "madness inside as hundreds of people tried to get out of the building".
He told reporters: "We had an active shooter in the end of the building behind me earlier today.
“Officers got here – got into the building very quickly."
He continued: "“We have several people shot.
“We’ve got fire working with our SWAT team and the initial officers on the scene to get as many people out as possible. Right now, it’s a quiet scene, so no one is actively shooting inside. We are doing a floor-by-floor, room-by-room search to make sure that we don’t have anybody else outstanding in the building.
“There’s no technical active shooter where someone is discharging rounds at this time."
An NBC reporter tweeted: "A man armed with a rifle has killed at least two, injured at least several others, and is himself believed to be deceased following an active shooter incident at St. Francis Hospital in Tulsa, OK according to multiple police officials."
While it is no longer an active shooter situation, officials are asking the public to avoid the area.
Tulsa Police Department tweeted: "Tulsa Police has responded to an active shooter incident near 61st & Yale.
"Please stay away from the area and yield to all emergency vehicles as we deal with this response. We will update the media as soon as we are able to gather details."
The Natalie Medical Building, part of the Warren Clinic where the shooting occurred, is primarily used for sports medicine and orthopaedic surgery.
Families were instructed to reunite at Memorial High School, police said. Authorities are asking people to avoid the area.
It comes a week after the horrific shooting at a Texas elementary school, where the burials are still taking place for 19 children and two teachers who were killed.
There have been at least 233 mass shootings in 2022 including yesterday's Tulsa shooting, according to non-profit organisation Gun Violence Archive.
The Gun Violence Archive defines a mass shooting as a shooting that injured or killed four or more people, not including the shooter.