Republican presidental candidate Ben Carson has claimed that arming German citizens with guns could have helped prevent the Holocaust.

In an interview with CNN, he said: "I think the likelihood of Hitler being able to accomplish his goals would have been greatly diminished if the people had been armed. I'm telling you, there is a reason these dictatorial people take the guns first."

Carson, a neurosurgeon, was defending earlier comments that he would go down fighting if he were facing a gunman similar to the Oregon college shooting. He told Fox News: "I would not just stand there and let him shoot me. I would say, 'Hey, guys, everybody attack him! He may shoot me but he can't get us all."

Defending himself for the comments, which have been widely criticised, Carson said: "To me that doesn't sound like a very controversial thing, but when you take it out of context and you try to make it look like I'm criticising the victims, that's when it becomes controversial. I would much rather go down fighting."

He said teachers should carry guns as a deterrent against shootings.

"Whether it's a kindergarten teacher who is well trained or a retired policeman or someone who can stop the carnage, I think it makes sense," he said, going on to suggest the Holocaust could have been militated against by allowing people to carry guns.

Carson also defended comments by media mogul Rupert Murdoch, owner of Fox, who tweeted: "Ben and Candy Carson terrific. What about a real black President who can properly address the racial divide? And much else."

Carson said Murdoch is entitled to his opinion. "I know Rupert Murdoch. He's not a racist by any stretch of the imagination. He's expressing his opinion. I think it's much to do about nothing."