WASHINGTON (AFP) - Republican presidential candidate Jeb Bush unleashed a torrent of criticism on Friday (Oct 3) when he said "stuff happens" when asked about renewed calls for gun control legislation after America's latest mass shooting.

Speaking at a conservative forum in South Carolina, Bush said the shooting that left 10 people dead and nine injured at a community college in Oregon was "just heartbreaking," and that he too had faced challenges during his time as governor of Florida.

"Look, stuff happens, there's always a crisis and the impulse is always to do something and it's not always the right thing to do," Bush said at the Conservative Leadership Project in Greenville, South Carolina, during a discussion about gun control.

He was guarding against the urge to press for new laws and regulations after tragedies like Thursday's shooting in Roseburg, Oregon.

Authorities said the shooter's 13 guns were all purchased legally by him or members of his family.

Representative Debbie Wasserman Schultz, who chairs the Democratic National Committee, jumped on Bush's comments.

"A message for Jeb Bush: 380 Americans have been killed in 294 mass shootings in 2015 alone. 'Stuff' doesn't just 'happen.' Inaction happens," she said on Twitter.

Amid the outcry on social media, President Barack Obama weighed in and was blunt.

"I think the American people should hear that and make their own judgments, based on the fact that every couple of months, we have a mass shooting," Obama told a press conference.

"And they can decide whether they consider that 'stuff happening.'" Bush insisted, however, that his comments had "no connection" to the Oregon shooting.

He later fought back on his Twitter feed.

"Liberal Dems & some in media distorted my words to advance their agenda in wake of tragedy. It's wrong. Thx to those who set record straight," he wrote.

He also posted a link to a fundraising campaign for the Oregon victims.

His spokeswoman Allie Brandenburger said her boss was not being dismissive and his comments were taken out of context.

"It is sad and beyond craven that liberal Democrats, aided and abetted by some in the national media, would dishonestly take governor Bush's comments out of context in a cheap attempt to advance their political agenda in the wake of a tragedy," Brandenburger said.

"Taking shameless advantage of a horrific tragedy is wrong and only serves to prey on people's emotions."