Madrid (AFP) - Furious and fearful over their toxic political crisis, Spaniards wrapped themselves in the national flag Saturday, yelling for their government to "defend the nation" against threats to declare Catalonia independent.

Gathering in Madrid, Barcelona and other cities, they vented anxiety that years of mistrust between the northeastern region and the rest of Spain could boil over -- but were divided over how to prevent it.

A further mass anti-independence rally in Barcelona was planned for Sunday. But already there and hundreds of miles away in Madrid, protesters were pleading for conservative Prime Minister Mariano Rajoy to heed calls for peaceful dialogue.

Others in the capital, waving red and yellow national flags and even some with the black eagle of the Franco dictatorship, vented patriotic fury.

- Anger -

In a fluttering sea of flags, tens of thousands of protesters in central Madrid banged drums and yelled "Viva Espana!" and "National unity!"

They demanded Spanish and Catalan leaders settle a dispute that last weekend sparked street violence in Barcelona during an outlawed independence referendum.

"Rajoy, you asshole, defend the nation!" chanted one angry group of mostly young men, marching towards Madrid's Colon Square.

- Fear -

Protesters accused the Catalan separatists of endangering Spain, but also said the national government had let things get out of hand.

Scenes of Spanish police beating unarmed Catalan voters as they tried to shut down last Sunday's vote shocked many Spaniards.

"There is a great deal of worry that the government has waited to play its last card too late," said off-duty cavalry colonel Joaquin Penas, 52, a flag on his back reaching nearly to his ankles.

A few hundred yards away down the tree-lined Recoletos avenue, another crowd of people in white held a quieter demonstration for peace and dialogue.

Yurena Diaz, a 36-year-old doctor, stood with her brown dog Quillo on a lead, said she wanted "dialogue before we lose our way."

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"The tension and violence have risen a lot. It is getting worse and worse," she said. "It has created a lot of fear and that is very dangerous."

- Tension -

Signs of a breathing space emerged on Friday when the government apologised to those hurt in last weekend's police violence.

But Catalan leaders have not ruled out unilaterally declaring independence. The government refuses dialogue or mediation until they drop their secession bid.

"This is the most tense moment I can remember in Spain in my lifetime," said demonstrator Fernando Pareja, a 19-year-old engineering student.

"I think most Spaniards support the police action but I also think they acted too late."

- Sadness -

At the "white" rally, actress Marta Muro, 67, in dark sunglasses, recalled Spain's past decades of deadly conflict in the state's battle against ETA armed separatists in its northern Basque Country region.

"I feel sad to think how bad our country is, how bad our government is," she said.

"I have nothing against the Catalans. We have to listen to them with respect and not with force or blood, like what happened with ETA."

- Hatred -

Natalia Bermejillo, a 21-year-old student, sat on steps with three friends near Colon Square.

She said she was not ashamed to join in a demonstration alongside small far-right groups, since they are supporting "the same cause" when it comes to Catalonia.

"If we do not join together there will be chaos," she said.

She felt hurt by the Catalan separatists' attitude to the rest of the country.

"They teach their children to hate Spain," she said.

"It is a very extreme ideology, and now it seems as if it is becoming contagious."