President Barack Obama condemns violence at Trump's California rally

Donald Trump, the presumptive Republican presidential nominee, has denounced the protesters as 'thugs'

US President Barack Obama has condemned the violence at a California rally of presumptive Republican presidential nominee Donald Trump, saying "that is not what our democracy is about".

"It is very important for us to remind ourselves of who we are and what is best about American democracy and not slip into some of the bad habits that currently manifest themselves in the other party," Obama said at a fundraiser in Florida.

"We saw in San Jose these protesters starting to pelt stuff on Trump supporters. That is not what our democracy is about. That is not what you do. There is no room for violence," he said.

"There is no place for shouting. There is no room for a politics that fails to at least listen to the other side even if you vehemently disagree because I believe if you have got the better argument, you do not need to do that. Just go out there and organise and persuade," Obama said referring to the violence against Trump supporters at a California rally.

Trump, 69, has denounced the protesters as "thugs" a day after another demonstration outside one of his rallies turned violent ahead of the state's presidential primary.

Democratic presidential front-runner Hillary Clinton, 68, also condemned the violence, saying this does not help anybody.

"I condemn all violence in our political arena. I condemned it when Donald Trump was inciting it and congratulating people who were engaging in it, I condemn it by those who are taking violent protest to physical assault against Donald Trump. This has to end," she told the CNN as she blamed trump for creating such an environment.

"He set a very bad example. He created an environment in which it seemed to be acceptable for someone running for president to be inciting violence, to be encouraging his supporters. Now we are seeing people who are against him responding in kind — it should all stop. It is not acceptable," she said. 

"I do not think any of this helps anybody. I do not think his protests that were led by his supporters, beating up people who were peacefully protesting against Trump, helped Trump and I do not think that people who are protesting and using physical violence against people supporting Trump are helping anybody, so I want it to just end," she added.

"I do not want to parse it, I do not want to talk bout the political implications. I want it to end. The police have a hard enough job trying to make sure that we are able to gather and talk about the issues facing our country and Trump has lowered the bar and now, is it a surprise that people who do not like him are stepping over that low bar? I do not think it is. He needs to condemn all violence by everyone. I already have, I will continue to do so," Clinton added.