Hacking group Anonymous has claimed that their members had engaged in a denial-of-service attack on the website for the Los Cabos Leaders' Summit of the Group of 20 (G20) www.g20mexico.org.

The attack coincided with the start of the seventh G20 Leaders' Summit at Los Cabos, a beautiful seaside resort in Mexico, Monday. The website could not be accessed until press time on Tuesday.

"We did it. We all participated," said a hacker with the IRC handle of @DICTADOR12 on aninternet relay chat (IRC) forum dedicated the hackers, adding that there would be more surprises Tuesday.

The group posted a You Tube video accusing the G20 leaders of being responsible for the bulk of the world's poverty, but made no attempt to deface the site itself, he said.

Computer staff at the summit site has denied that there had been a hackers attack, saying that services were down due to a separate technical problem.