(AFP) - Spain was plunged into crisis Friday as Madrid seized power from independence-seeking Catalonia, the first curtailment of regional autonomy since the brutal dictatorship of Francisco Franco.

After regional lawmakers voted to declare a Catalan "republic", Spanish Prime Minister Mariano Rajoy moved swiftly to dissolve the rebel government and parliament, and called December 21 elections to replace them.

In an escalating standoff closely watched by secession-wary Europe, Rajoy fired pro-independence leader Carles Puigdemont and all his ministers as well as the director of the regional police, and Catalan envoys to Madrid and Brussels, to halt what he termed an "escalation of disobedience."

Secessionist lawmakers voted 70 to 10 in the 135-member parliament Friday to declare Catalonia "a republic in the form of an independent and sovereign state".

They take their mandate from the "Yes" result in a banned and unregulated October 1 independence referendum spurned by many more than half of Catalan electors.

Observers warned of trouble ahead, with Catalan officials and public servants likely to defy orders from caretaker envoys sent by the central government.

"Tensions are likely to rise significantly over the coming days," suggested Teneo Intelligence, a risk analysis group.

"Demonstrators might try to prevent the police from removing Catalan ministers from their offices... This increases the risk of violent clashes," it said in a statement.

- 'Demolished democracy' -

The region of some 7.5 million people accounts for about 16 percent of Spain's population, a fifth of its economic output, and attracts more tourists than anywhere else in the country.

Catalonia´s inhabitants are fiercely protective of their language, culture and autonomy -- restored after a long period of oppression during nationalist Franco´s 1936-1979 rule.

In Barcelona, separatists broke out in ecstatic shouts of: "Independence!" and popped bottles of cava, a Catalan sparkling wine, as the outcome of Friday´s vote was announced. Separatist MPs cheered and embraced before singing the Catalan anthem.

But any cause for joy was soon nipped in the bud, and shares in Spanish companies, particularly Catalan banks, dropped sharply as the crisis deepened.

"We Spaniards are living through a sad day in which a lack of reason prevailed upon the law and demolished democracy in Catalonia," Rajoy said as he announced steps to "restore normality".

The sweeping measures were approved by the Senate Friday under a constitutional article designed to rein in rebels among Spain's 17 regions.

Madrid's allies in the European Union and the United States rallied behind Madrid as they voiced alarm over developments in Spain´s worst political crisis in decades.

European Council President Donald Tusk said Madrid "remains our only interlocutor" following the independence vote.

"I hope the Spanish government favours force of argument, not argument of force," he tweeted.

Steffen Seibert, spokesman for German Chancellor Angela Merkel, said Berlin "does not recongise such a declaration of independence" by Catalonia.

- Battle of wills -

The issue is far from a clear-cut battle of wills between Madrid and Catalonia, however.

Polls show Catalans themselves are split, pretty much down the middle, on the issue of independence from Spain.

Dozens of opposition MPs walked out before Friday´s secret ballot in the Catalan parliament, one lamenting "a dark day" for democracy.

Later in the day, hundreds of anti-independence protesters gathered in central Barcelona, chanting "I am Spanish, Spanish!"

Waving the Spanish flag, several demanded Puigdemont be jailed for sedition, even as prosecutors announced they would file "rebellion" charges against him next week.

He risks up to 30 years in jail.

But outside the seat of the Generalitat, the Catalan government, the mood was festive, with fireworks and music.

"We are a free country," revelled Maria Altimira, 65.

- Disobedience -

Catalan resentment at Madrid's perceived interference has been building for years, compounded by the 2008 economic crisis. Many complain that the region contributes more to the central purse than it gets back.

The UN urged both sides Friday to "seek solutions within the framework of the Spanish constitution, and through established political and legal channels."

But far-left groups have already threatened "massive civil disobedience" if Madrid usurps Catalan autonomy.

"We are likely to see more sustained unrest, possibly including strikes, as well as more serious clashes between national police and pro-independence activists," said Federico Santi, an analyst at Eurasia Group, a US-based politics think-tank.

"The main signpost over the weekend will be whether the regional government refuses to willingly and peacefully step down."

- Call for restraint -

Puigdemont appealed for calm.

"We will have to maintain the momentum of this country (Catalonia) in the coming hours," he told lawmakers and onlookers in Barcelona after the legislature vote, and urged them to do so in the spirit of "peace, civic responsibility and dignity."

There are deep concerns over the economic impact of the showdown, with nearly 1,700 companies already having moved their legal headquarters out of Catalonia, which has an economic output equivalent to that of Portugal.

© Agence France-Presse