Hacker outfit  Anonymous may have bitten off more than it could chew over the weekend. It made a much publised assault on Spain's national police force and knocked over the website for an hour.

Spanish newspaper El Mundo said the group had warned police in a statement that it planned to disable the website at some time on Saturday. The attacks follow the arrest of  three suspected members of the group on Friday on charges of cyber attacks against targets including the websites of Sony, governments, businesses and banks.

It is thought the trio were involved in the hacking of PlayStation network. However, Anonymous recently denied that the three arrested suspects were a "core group", as the police claimed.