NEW YORK - A filmmaker who was behind documentaries that bashed Rupert Murdoch and Wal-Mart is now focusing on Rudy Giuliani, creating an "online viral video campaign'' about the presidential candidate timed to coincide with the anniversary of the Sept. 11 attack.

Robert Greenwald on Thursday launched the first of four short videos about Sept. 11 and the Republican former mayor. The others are planned to launch throughout the month.

The videos attack Giuliani by saying he failed to prepare New York City for a major disaster, he ignored sick ground zero workers after the terrorist attack and he profited financially from his association with the tragedy after leaving office in 2001.

"We want to use this forum to reach people and show and tell and say, 'Look here are some truths that we want you to know,''' Greenwald told The Associated Press. The video blitz has an accompanying website, .

The Giuliani campaign questioned Greenwald's motivation and timing.

"It's unfortunate that a conspiracy theorist so disconnected from reality would launch a politically motivated hit video to coincide with the anniversary of the Sept. 11 terrorist attacks,'' said Mike McKeon, a Giuliani spokesman.

Greenwald, a Brooklyn native and registered independent, has made a number of documentaries, including "Outfoxed: Rupert Murdoch's War on Journalism'' and "Wal-Mart: The High Cost of Low Price.''

He said he was inspired to create the Giuliani videos earlier this year after learning about Giuliani's critics, who have begun to turn up the heat on the former mayor as his presidential campaign has taken off.

The spots feature interviews with many of those known critics, including relatives of those who died in the World Trade Center attack, fire safety experts and Jerome Hauer, Giuliani's emergency management commissioner from 1996 to 2000, who had a falling out with his boss in 2001.

Greenwald said each video cost about US$40,000 to make and that fundraising helped pay for the series, which will be posted on YouTube and emailed to bloggers, supporters and other venues. He is also exploring the idea of buying television time for the spots in some of the early primary states.

Other work by Greenwald and his company, Brave New Films, during this presidential campaign includes a short film for MoveOn.org's campaign to get the Nevada Democratic Party to drop Fox News Channel as a co-host for an August debate. It was eventually cancelled.

Greenwald said he is not supporting any candidate yet.

Meanwhile, Giuliani, who was campaigning in Minnesota Thursday, downplayed the entrance of former Tennessee Sen. Fred Thompson into the presidential race. Giuliani said he didn't think the campaign had changed for him with the addition of the new GOP candidate.

"I don't run against any other Republican, I run against Democrats,'' he said.