NEW YORK (Reuters) - An invisible cyber assault has cut off access for the second day running to the Web site of the World Economic Forum, organizers of the gathering of the world's political and business elite confirmed on Friday.

The flood of Internet traffic to the Web site at  http://www.weforum.org began on Thursday afternoon, the first day of a five-day conference, and continued through Friday, with only intermittent let-up, a conference organizer said.

``What we do know is that too many hits on our Web site are shutting it down,'' spokesman Charles McLean told a briefing for reporters attending the summit on Friday.

``If it's in fact vandals, that's unfortunate because we are in the dialogue business and dialogue involves communication,'' he said. The Web site ``is a way for us reaching out to people out in the streets.''

The shutdown appeared to be an example of a common type of computer vandalism known as a ``denial of service'' attack. This involves overwhelming a site with false computer requests, rendering the information inaccessible to legitimate users.

Law-enforcement sources confirmed details of a Village Voice online account of the cyber vandalism on the World Economic Forum (WEF) Web site, making it the second year in a row in which the event's Internet site has come under attack.

Last year, hackers broke into the WEF site and gained access to a private list of 27,000 names, including personal details such as credit card data and phone numbers of participants. An unidentified group of hackers calling themselves ``Virtual Monkeywrench'' took credit for that action.

The World Economic Forum annual meeting allows many of the world's most powerful leaders to attend exclusive workshops to discuss issues ranging from the root causes of violence to reviving global economic growth to lighter cultural themes.

This year's meeting of 2,700 delegates takes place in New York under tight security that has cordoned off several busy blocks of midtown Manhattan.

The event was shifted to New York from the ski resort of Davos, Switzerland, where it had been held for 31 years -- in a gesture of solidarity with the city scarred by the Sept. 11 attack on the World Trade Center.

However, the event also has been the occasion for protest by critics who complain that the summit is a talk-shop for the rich that fails to result in substantive change. So far protests have been limited, but a street march is scheduled for Saturday near the hotel where the event is being held.

HACKERS TAKE CREDIT

New York-based Village Voice newspaper said in its online edition that the Electronic Disturbance Theater, RTMark, and Federation of Random Action have taken credit for crashing the Web site.

According to law-enforcement professionals a group calling itself ``The Yes Men'' released version 2.0 of Reamweaver, their automatic Web site parody software, and set it loose on the WEF Web site.

The software allows users to instantly redirect visitors from a site such as the official WEF home page to a new site dictated by users of the parody software. At the same time, Reamweaver allows users to change any words they choose.

For example, the first line on the official WEF Web site, ''Reducing Poverty and Improving Equity,'' is turned into: ''Reducing Uselessness and Improving Profit-Sharing.''

``The Web site is one of the key ways of offering transparency and showing people what we are doing here,'' McLean said, but dismissed the breakdown as a nuisance rather than a major event.

He added that his organization had hoped to use the site to make portions of the event available to the public, answering criticism that the event was secretive.

``We would like to broadcast plenary sessions here,'' McLean said, referring to events at which speakers ranging from the Secretary of State Colin Powell to rock star activist Bono have appeared.