Washington, US (BBN)-Hillary Clinton has attacked her main rival Bernie Sanders on gun laws at the Democratic presidential debate.
When asked if the Vermont senator was strong enough on guns, she said "no, not at all" before vowing to go after the makers of guns used in shootings, reports BBC.
Sanders also attacked Clinton, saying her support for a no-fly zone in Syria would create "serious problems".
His rallies have drawn big crowds and he has challenged Mrs Clinton's frontrunner status in some key states.
A lot of the key exchanges came between these two and the three other candidates on stage in Las Vegas - former Maryland Governor Martin O'Malley, former Virginia Senator Jim Webb and former Rhode Island Senator Lincoln Chafee - struggled to make headway.
Highlights so far:
biggest applause of the night to Sanders when he said the country was "sick" of hearing about Clinton's email controversy
when accused of political expediency, Clinton said: "I'm a progressive who gets things done"
former first lady said she would stand up to "bully" Russian President Vladimir Putin
but she was on the defensive for supporting Iraq War and backing a no-fly zone in Syria
O'Malley defended his record as mayor in Baltimore, where there were riots this year
Vietnam veteran Webb said his military service gives him leadership skills
one of my strengths is I've never had a political scandal, said Chafee
Clinton said she wants to be judged on her record not her surname
she said whistleblower Edward Snowden "needs to face the music" and return to the US but Sanders said he did important work educating the nation about government collection of personal data
One of the sharpest points of difference between the two main candidates came over gun laws.
The hugely divisive issue came back on the agenda after a mass shooting at a college campus in Oregon.
When Mrs Clinton said her rival was not tough enough, she was referring to him voting in 2005 for a measure to give gun manufacturers immunity from lawsuits.
The two also argued over the merits of capitalism, with the former first lady saying it would be a "grave mistake" for the nation to reject it.
Vice-President Joe Biden is still considering a run for the White House and did not make a last-minute entry on to the stage, as his supporters hoped.
Clinton has seen her support wane amid questions about her use of a private email account when she served as US secretary of state, a move she now calls a mistake.
However, she was unfazed during the debate when Chafee questioned her credibility over it, refusing to respond when invited.
More on the Democratic presidential race
Meet the Democratic debaters - The candidates include a self described "democratic socialist", a war veteran and a former Republican.
A widening gap between Clinton and Obama - Clinton's alliance with Obama was always a bit of a marriage of convenience.
Hillary's hard and painful road to 'sorry' - Her mea culpa indicates a change of strategy as the candidate struggles to find her footing.
Democrats are feeling the Bern - Sanders has given voice to the frustration and anger that some on the left feel over the current state of US politics.
The candidates tried to draw a distinction with the two Republican debates, where candidates took a tougher stance on immigration and spent more time discussing social issues like abortion and gay marriage.
O'Malley used his 90-second closing speech to say the Republican debates were lessons in intolerance.
But Republican candidate Jeb Bush said he saw nothing on the Las Vegas stage to impress him.
"If you think this country is on the wrong track, Hillary Clinton just told you she has no interest in changing direction. I sure will."
Fifteen Republicans are vying to be the party's White House nominee in 2016.
Iowa will be the first state to choose its candidate from each party in February, then other states hold primaries in the following weeks and months.
By next summer, each party will have a presidential nominee who will do battle in the race for the White House.
Votes will finally be cast in November 2016.
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