Washington (AFP) - More than 22,000 people have signed a petition calling for Americans to be allowed to carry firearms at the Republican National Convention -- because the ban puts lives at risk.

Guns are not allowed inside the Quicken Loans Arena in Cleveland, where the event -- which could descend into a heated battle for the party presidential ticket -- is taking place in July.

The petition went up on the Change.org website and by Saturday had been signed by 22,633 supporters in just a few days, with numbers rising fast.

"Cleveland, Ohio is consistently ranked one of the top 10 most dangerous cities in America," says the petition, which among others is addressed to the Republican presidential frontrunner Donald Trump and his rivals Ted Cruz and John Kasich.

"By forcing attendees to leave their firearms at home, the RNC and Quicken Loans Arena are putting tens of thousands of people at risk both inside and outside of the convention site."

In the event of an attack on the venue people there "will be sitting ducks," raising the specter that the Islamic State extremist group could target it, the petition says.

"We are all too familiar with the mass carnage that can occur when citizens are denied their basic God-given rights to carry handguns or assault weapons in public," the petition adds.

Firearms were banned by the Secret Service at the Republican convention in Tampa in 2012, US media say.