Council officials decided to curb the charity practice, with possible fines of $1,000 and six months imprisonment, after complaints from residents.

Other US cities have rules or have looked at limiting free food giveaways.

Las Vegas is thought to be the first to explicitly make it an offence to feed the poor, says the New York Times.

The city's homeless population has doubled in the past decade to about 12,000.

Officials said the ban was not aimed at casual handouts from Good Samaritans, the newspaper reported, but at so-called "mobile soup kitchens".

It was devised after residents complained that the large numbers of people gathering to use such services make it impossible for other residents to use the parks, city spokesman David Riggleman said.

He added that ending the soup kitchens' operations would encourage homeless people to go to a centre or charity offering services such as mental health evaluations or job placements.

Under the new law, which takes effect on Saturday, anyone offering food or drink to a homeless person will risk a $1,000 fine and six months in jail.

'Community responsibility'

Speaking on BBC Radio 4's World Tonight programme, Las Vegas attorney Brad Jerbic defended the new law, saying homeless people should not receive help inside the park.

"If you were to provide a hot meal to somebody in a nice shady park as opposed to maybe a soup kitchen where they have to wait in line longer maybe it's an attractive thing, but at the same time once you leave the rescue mission, once you leave the shelter, you're left alone in that park.

"No bed, no doctor, no social service provider, and the neighbourhood has to pick up the problem."

But Gail Sacco who has been operating one such food kitchen for the past year told the BBC she would not obey the law.

"I will do whatever is necessary to keep them alive," she said.

"It should be a community responsibility."