Edinburgh, August 11 : American law enforcement agencies have expressed fear that US presidential candidate Barack Obama will be the target of a violent attack by white supremacists at the Democratic convention in Denver this month.

According to a report in the Scotsman, the concern for Obama''s security is because of racist threats made against him by neo-Nazis, the Ku Klux Klan and similar groups, since the Senator for Illinois emerged as the likely Democratic presidential candidate.

"I''m not going to have to worry about him, because somebody else down south is going to take him out," said Railton Loy, Grand Wizard of the National Knights of the Ku Klux Klan International in an interview on Fox News.

"If that man is elected president, he''ll be shot sure as hell. The hate would be so deep down south," he added.

Meanwhile, websites and blogs have also been buzzing with racist posts.

"Obama will die, KKK forever," said a post by "Rodney" on a blog run by a person identified only as Strider333.

"The KKK or someone WILL assassinate Obama! If we get a N***** President all you N*****''s (sic] will think you''ve won and that the WHITE people will have to bow to you F*** THAT," he added.

"People on these racist and white supremacist websites are being quite careful because they know that if they make a threat they will very likely get a visit from the Secret Service," said Mark Potok, an expert on the radical right at the Southern Poverty Law enter in Montgomery, Alabama.

"The scary thing out there is the lone wolf phenomenon. There are enough crazy people in this movement that it is possible one of them will decide today is the day to kick off the Aryan revolution," he added.

John W Hickenlooper, the Democrat Mayor of Denver, confirmed that he was aware of threats against Obama from white supremacists and other racist groups.

He added that the Denver Police Department was working closely with the Federal Bureau of Investigation and the Secret Service.

"We are looking at every possibility and making sure that we have prepared for every conceivable contingency. If someone is threatening violence, we will go to great lengths to deal with that," said Hickenlooper.

The federal government is providing Denver - and St Paul, Minnesota, where the Republicans are staging their convention at the start of next month - with 50 million dollars each to cover the security costs of staging the conventions.

The Denver Police Department will nearly double in size, bringing in an additional 1,500 police officers from communities throughout Colorado and beyond.

National Guard specialists trained to deal with biological, chemical, nuclear and radiological weapons will also be available.

Obama was placed under Secret Service protection in May 2007, the earliest ever for a candidate for the presidency. (ANI)