Presidential hopeful Donald Trump has brushed aside claims that lax guns laws in the US are to blame for Wednesday's mass shooting at an Oregon community college.

Speaking to NBC's Meet the Press about President Barack Obama's comments following the killings, Trump put the blame on mental illness. Calling the shooter "sick," he said Us gun culture is not at fault:

“No matter what you do – guns, no guns – you have people that are mentally ill. And they’re going to come through the cracks. And they are going to do things that people will not even believe are possible,” he said.

The controversial business tycoon, who continues to top polls in the Republican primaries, did admit that such mass shootings were more prevalent in the US than elsewhere, and suggested many could be a result of a copycat effect.

He said such attacks are near impossible to prevent."You can have the best security, you can have the best everything, but people are able to get in and do this terrible damage," he said.

Nine people were killed and seven injured when a 26-year old student of Umpqua Community College opened fire on its campus.

Following the incident, Mr Obama warned against the routine of mass shootings that has developed in the US, and reiterated his support for tightening laws on guns. He said the country had become "numb to such violence."

The US has averaged almost one mass shooting per day since the beginning of 2013.