By Steve Kingstone
BBC News, Madrid
Demonstrators signed petitions calling for a referendum on independence
Thousands of demonstrators have taken to the streets in the Basque region of Spain, demanding the right to a referendum on independence.
The regional government had originally planned to hold a vote on Saturday, but the proposal was declared illegal by Spain's Supreme Court.
Organisers say 20,000 people joined rallies in six Basque towns.
In another sign of protest against the court's ruling, there were explosions at two Basque railway stations.
The governing Basque Nationalist Party had hoped to consult the electorate on Saturday on negotiations towards a full referendum on independence within two years.
But last month, Spain's Supreme Court declared the plan unconstitutional.
During Saturday's march, police had to separate Basque nationalist demonstrators from a rival rally by a far-right party - which proclaimed that Spain would never be divided.
Overnight, there was a very different protest in the form of explosions at two Basque railway stations.
Shortly after midnight, a small bomb brought down the ceiling of a ticket hall in the town of Berriz. Two hours later, petrol bombs were hurled at ticket machines in the nearby town of Amorebieta. There were no injuries.
Speaking at the EU-Asia summit in Beijing, the Spanish Prime Minister, Jose Luis Rodriguez Zapatero, condemned the attacks and said terrorists would be punished.
Police are investigating whether the bombings were the work of the armed separatist group ETA or young nationalist sympathisers.
Mr Zapatero has portrayed the proposed referendum as political manoeuvring ahead of regional elections next March.
But in a newspaper interview, the head of the regional government - Juan Jose Ibarretxe - said Madrid had shown an arrogant disregard for the rights of the Basque people.