Several anti-war protesters have disrupted John McCain's speech, shortly after he accepted the presidential nomination.
One of the protesters, who managed to sneak into the crowd, held up a sign reading ‘You can't win an occupation.’
Another protester in another part of the arena started shouting slogans, but was hastily escorted out by security.
The crowd meanwhile, tried their best to drown out the slogans by shouting ‘USA, USA!’
McCain brushed them off, resuming his speech and declared himself the only choice for voters who want an end to gridlock in Washington, and the tradition of politicians who only work for themselves.
He has officially accepted the Republican presidential nomination, warning Washington politicians change is coming.
The four-term Arizona senator was met with extended applause from delegates to the Republican National Convention, and guests crammed into the Excel Energy Centre.
McCain was seriously honing in on Democratic candidate Barack Obama's message of change, apparently hoping to blunt the Democratic assertion that a McCain victory on November 4 would mean four more years of the polices of unpopular President George W Bush.
The Republican standard-bearer was taking on a precarious task to present his credentials as a reformer willing to challenge his own party, and stressing his independence from Bush without alienating his base.
"Let me offer an advance warning to the old, big spending, do nothing, me first, country second Washington crowd: change is coming," McCain said.
He opened his speech with a bow to Obama, saying, "You have my respect and admiration. Despite our differences, much more unites us than divides us."
But he made it clear he would not let that stop a vigorous campaign. "Let there be no doubt, my friends, we're going to win this election."