* Protest over police crackdown on Sunday's referendum
* Public transport, roads, services affected
* Thousands of protesters march through Barcelona (Adds color, background)
BARCELONA, Oct 3 (Reuters) - Metro stations were closed in Barcelona, pickets blocked roads and state workers walked out on Tuesday in protests across Catalonia over a Spanish police crackdown on a banned independence referendum.
The stoppages, in response to a call for a general strike by pro-independence groups and trade unions, affected the public sector, public transport and basic services.
The atmosphere in Catalonia has been feverish since the Spanish government sent in police on Sunday to stop an independence referendum that had been banned by Spanish authorities, injuring hundreds of people as they tried to vote.
Results showed voters overwhelmingly backed independence in the ballot, which opponents of secession mostly boycotted.
The referendum has plunged Spain into its worst constitutional crisis in decades.
Catalan leader Carles Puigdemont has said the vote was valid, raising the prospect that the Catalan parliament could unilaterally declare independence from Spain within days. Puigdemont has also called for international mediation in the region's dispute with Madrid.
Catalonia, Spain's wealthiest region, wedged in the northeast on the Mediterranean coast below the mountainous border with France, has its own language and culture, and a growing minority there has nurtured hopes of independence for years. Madrid says the constitution prohibits secession and can only be changed if all Spaniards, not just Catalans, agree.
Catalonia is a center of industry and tourism accounting for a fifth of Spain's economy. Although it has extensive autonomy, its tax revenues are crucial to Spain's state budget.
Spanish stocks remained under pressure and the cost of insuring exposure to Spanish sovereign debt rose to a near five-month high, with many economists and investors anticipating an escalation of tensions in the short term.
Thousands of people took part in marches and protests in Barcelona, the regional capital, on Tuesday.
A big crowd gathered outside the local headquarters of Spain's ruling Popular Party. Catalan firefighters in their orange jackets and yellow helmets, who have assumed a role as mediators between demonstrators and police, stood between the crowd and police.
"In no way can we accept that they come here with this kind of repression," taxi driver Alejandro Torralbo, 64, said of Sunday's police action.
"They can't do this. What happened on Oct. 1 has fired up independence feeling that will never die," said another demonstrator, 18-year-old student Monica Ventinc.
Normally busy metro stations in Barcelona were deserted as services were cut back sharply, pickets blocked traffic on Gran Via street and traffic on six major highways in the region was disrupted by protests.
Protesters used a large truck to block a highway in El Masnou near Barcelona, painted "general strike" on a road sign and put up a banner reading "Not one step back."
"Today is a day of democratic, civic and dignified protest. Don't let yourselves be carried away by provocations. The world has seen that we are peaceful people," Puigdemont said on Twitter on Tuesday.
Elsewhere in Barcelona, the response to the strike call was patchy with some shops, supermarkets and cafes open and some closed. The Boqueria market in the city was almost empty.
With 95 percent of the vote counted, authorities said the "Yes" vote stood at 90.1 percent, on a turnout of 2.26 million of 5.34 million registered voters.
The Catalan government said almost 900 people were injured when Spanish police forcibly tried to close polling stations.
Prime Minister Mariano Rajoy has defended the police action and said more than 400 police officers needed medical attention.
Scenes of armored Spanish police swinging truncheons and firing rubber bullets at peaceful voters have been widely condemned, with the European Union calling for talks to break the stalemate between Madrid and Barcelona.
On Sunday, Rajoy said the ballot had failed, while Puigdemont vowed to continue with the independence process.
Spain's two largest unions, the UGT and CCOO, said on Monday their affiliates in Catalonia would not take part in the general strike, but would support protests.
Spanish Deputy Prime Minister Soraya Saenz de Santamaria said police had told her they had been forced to leave one Catalan town after the local council threatened to exclude them from the hotels where they were staying.
"We aren't going to tolerate mafia-like behavior from the town councils of Catalonia," she said.
Many services under the control of the Catalan government saw some stoppages, with public transport running at around 40 percent, according to reports, while port workers and civil servants also walked out. Entrances to some government offices were blocked by crowds protesting in favor of independence.
In the small Catalan town of Vic, a bastion of independence, every shop, bar and cafe was closed in the town of 40,000 people and stalls were draped with Catalan flags, which also hung from most balconies.
A giant "yes" banner hung in the main square, where people were congregating. A neon sign above a closed bar on the square flashed "Hello New Country, Hello New Republic, Hello Europe."
(Additional reporting by Angus Berwick in Vic, Robert Hetz and Sonya Dowsett in Madrid; Writing by Paul Day and Adrian Croft; Editing by Julien Toyer and Janet Lawrence)