Image copyright AP Image caption Duke, seen here in 2004, said he wants to return to politics

David Duke - a former leader of the Ku Klux Klan - has launched a campaign for an open seat in the US Senate.

Duke is one of more than 20 candidates seeking the seat vacated by Republican Senator David Vitter of Louisiana.

The white nationalist has been an outspoken supporter of Republican presidential nominee Donald Trump.

The Republican previously served as a Louisiana state lawmaker from 1989 to 1992 and unsuccessfully ran for governor.

"I believe in equal rights for all and respect for all Americans," Duke said in a video posted to his website.

"However what makes me different is I also demand respect for the rights and heritage of European Americans."

He enters the race amid a rise in racial tensions in Louisiana. This month, Baton Rouge police shot and killed a black man as he was being held to the ground. The shooting - captured on video - led to protests across the country.

On Sunday, a black gunman shot and killed three police officers in Baton Rouge. Authorities said the gunman, Gavin Long, lured the officers into an ambush.

Image copyright Twitter Image caption Duke praised Mr Trump's convention speech on Twitter

Duke returned to the national spotlight in February when he endorsed Mr Trump for president. Mr Trump was sharply criticised when he did not initially disavow the endorsement.

"I'm overjoyed to see Donald Trump and most Americans embrace most of the issues that I've championed for years. My slogan remains America first," Duke said on Friday.

In Louisiana, all candidates - regardless of party affiliation - run on the same ballot. A run-off election is held if no candidate receives a majority of the vote.

Republican Congressman Charles Boustany and state Public Service Commissioner Foster Campbell, a Democrat, are considered among the front-runners in the crowded race.

Duke pleaded guilty to tax fraud in 2002 and spent a year in federal prison.