CATALAN nationalist groups suffered waves of cyber attacks as they organised a public consultation on independence from Spain.

What appeared to be an orchestrated campaign brought down the websites of the north-eastern Iberian nation's government and various voluntary bodies helping to carry out the weekend ballot.

The mobile phones of activists were also hit by thousands of repeated calls - every 30 seconds - without anyone being on the line when they answered.

Fewer than half the electorate of Catalonia turned out for the poll on Sunday but four-fifths of those who did backed independence.

Analysts believe the vote, which was held after a binding, Scottish-style referendum was blocked by the Spanish courts, amounted to another demonstration of the kind that have mobilised hundreds of thousands of people in recent years.

The Generalitat, the government of Catalonia, has said Catalan groups were subject to nine out of 10 cyber attacks in the world last weekend. The crude nature of the action has led to speculation in the Spanish press they were the work of anti-separatist hackers.

Many Catalans suspect foul play by the Madrid government but this has been denied.

Catalan President Artur Mas has called for a new dialogue with Madrid while SNP allies Esquerra want new elections.