Two TV journalists have been shot dead on air in central Virginia, the general manager of a US TV station has said.

Jeffrey A Marks, general manager of WDBJ-TV, identified the two killed as reporter Alison Parker and cameraman Adam Ward.

The station says in tweets and in a story on its website that the incident happened at a shopping centre. 

Mr Marks said: "It is my very, very sad duty to report that we have determined through the help of the police and our own employees that Alison and Adam died this morning shortly after 6.45 after the shots rang out."

"We do not know the motive, we do not know who the killer is.

"I just got off the phone with the state police they are working very diligently to track down both the motive and the person responsible for this crimes against two very fine journalists."

He added: "I cannot tell you how much they were loved, Alison and Adam, by the WDBJ7 team.

"Our hearts are broken and our sympathy goes to our entire team but also their parents and families of Alison Parker and Adam Ward, who were just out doing their job today covering a story near Smith Mountain Lake.

"We have members of the team holding back tears frankly."

Parker was on her last day on the job before starting employment elsewhere.

SHOOTER WAS EX-EMPLOYEE  

Virginia Governor Terry McAuliffe said the suspected shooter  has been identified and appears to be a disgruntled former employee from the station, local media reported.

The suspect was pursued by police and shot himself.