Donald Trump's campaign events have apparently become such a minefield for reporters that one major news organization has taken the extraordinary step of offering its correspondents a version of training for dealing with real minefields.

Donald Trump's campaign events have apparently become such a minefield for reporters that one major news organization has taken the extraordinary step of offering its correspondents a version of training for dealing with real minefields.

NPR has sent its political reporters to 90-minute hostile-environment awareness training, which in its typical form lasts a few days and prepares journalists for covering war zones or regions where terrorists are active.

News organizations, government agencies and nongovernmental organizations generally employ such training to help employees respond to such hazards as riots, mortar attacks, kidnappings or firefights.

In this case, NPR's scaled-down sessions might be called Trump Training.

Although there have been no mortar attacks, Trump's campaign rallies are generally rowdy affairs in which violence has occasionally flared. The candidate canceled one of his rallies in Chicago this month out of concerns that protests against him had become too volatile.

Three journalists have been roughed up while covering Trump, including a reporter for Breitbart News who suffered bruises earlier this month when she said she was grabbed by Trump's campaign manager, Corey Lewandowski, as she was questioning Trump. Lewandowski has denied involvement, and Trump has defended him.

But Trump arguably has inflamed violent behavior among his supporters by declining to disavow their behavior. He has said he wanted to punch one protester "in the face" and that protesters in an earlier age would "be carried out on a stretcher, folks."

He has also suggested that riots could ensue if he is denied the nomination at the Republican convention despite securing the leading share of delegates.

NPR wouldn't discuss its training in detail, but Michael Oreskes, senior vice president of news, confirmed that the radio and digital news organization has made it available to its reporters. He described it as training for "dangerous or possibly hostile environments."

A spokeswoman, Isabel Lara, said the sessions are designed to deal "with the stress of covering a very demanding story for a long period of time. We make the training widely available to newsroom staff whether they work internationally or domestically."

She declined to say how many staffers had received the training.

NPR appears to be alone in providing such training to its Trump reporters. No other news organization, including The Washington Post, said it was undertaking similar training, according to a spot check.

Frank Smyth, executive director of Global Journalist Security, a firm that provides hostile-environment awareness training (HEAT), said some news organizations sought his company's services last year after a disgruntled former employee of a TV station shot and killed a reporter and her cameraman at a Virginia resort.

Although no one has asked about Trump rallies specifically, he said, "This violence is a serious concern, and it has the potential to escalate and develop a momentum of its own that could lead to serious injuries of journalists. In other words, I am more concerned about the kind of climate this could help unleash than the level of violence against journalists we have seen to date."