1110 GMT: The general strike in Spain, which started overnight with pickets at factories, train stations and markets, seems to be having a major impact.
Police have arrested 62 people, while 34 people have been injured -- 18 of them police -- in "isolated incidents" amid the protests, said a spokeswoman for the interior ministry.
Electricity use is down 15.8 percent from the normal rate, a sign of the impact on industry, while many train, bus and metro services have ground to a halt.
"They are taking away our future!" declare banners strung up around central Madrid. One in four of the country's workers is currently unemployed.
1100 GMT: WELCOME TO AFP'S LIVE REPORT on the unprecedented wave of strikes and protests across Europe on Wednesday.
Workers in Spain, Portugal, Greece and Italy are taking strike action over deep government cuts prompted by Europe's debt crisis, while union-led rallies in solidarity are planned in France, Belgium, Germany and Poland.
More than 700 flights are grounded and factories have ground to a halt amid what the European Trade Union Confederation said are the first simultaneous strikes in four European countries.
"14-N" -- the shorthand for November 14 being used to describe the strikes -- is trending on Twitter worldwide, while hundreds of web users are posting photos of banner-wielding workers who have taken to the streets.
In Spain, where picketing began overnight, police are clashing with hundreds of young protesters in central Madrid as officers try to disperse crowds and stop them blocking the main Gran Via avenue, according to AFP journalists at the scene.
Stay with us for regular updates from AFP's correspondents around Europe.