Police in Spain made dozens of arrests during clashes with protestors for a second consecutive night as demonstrators took to the streets to denounce the new coronavirus restrictions.
In some cities, looting and vandalism broke out late on Saturday on the fringes of the protests.
The biggest disturbances were in Madrid where scores of demonstrators chanting "freedom!" torched rubbish bins and set up makeshift barricades on the city's main thoroughfare, the Gran Via, images on social media showed.
When police moved in to clear the gathering, they were pelted with stones and flares.
Twelve people, including three police officers, were lightly injured in the clashes, emergency services said. Police said they arrested 33 people.
The head of the regional government of Madrid, Isabel Diaz Ayuso, blamed the unrest on "organised groups looking to take advantage of the situation and people's fears".
"The people sowing chaos on the streets are not those most vulnerable to the virus, nor are they the ones fighting for their lives," she added in a tweet.
In Logrono, the capital of the northern wine-producing region of La Rioja, a small group of people burned garbage bins and smashed shop windows.
The trouble broke out following a peaceful protest against the closure of restaurants and bars in the region as part of widening virus restriction in Spain.
Hooded youths wearing face masks ran out of a clothing shop with armfuls of items in their hand as a security alarm blared, images on local media showed.
The looters broke mannequins, destroyed a computer and took money from the cash till, the owner of the shop, Cristina Perez, told a local television station.
"We earn our living working and in five minutes they destroyed our lives," she said.
Police arrested seven people in Logrono, a national police spokeswoman said. Another ten people were detained in protests held in the northern cities on Bilbao and Santander, she added.
At least one person was arrested in the southern city of Malaga a small group of demonstrators overturned rubbish bins and threw bottles at police.
- 'Violent and irrational' -
Prime Minister Pedro Sanchez condemned the unrest. "Violent and irrational behaviour by minority groups is intolerable. It is not the way," he tweeted.
"Only from responsibility, unity and sacrifice will we be able to defeat the pandemic that is devastating all countries."
Sanchez later thanked a group of young people who took to the streets of Logrono on Sunday morning to clear debris, calling it an "admirable reaction" in a tweet which included a link to a TV report about the initiative.
"The youth of our country is this: generosity, responsibility, commitment. Values that enhance us as a society," he added.
At least 20 police officers were injured on Friday night in clashes with protesters in central Barcelona and 12 were arrested.
Spain last week imposed a nationwide nighttime curfew to try to halt the rise of Covid-19 infections and almost all of Spain's regions have imposed regional border closures to prevent long-distance travel.
Health Minister Salvador Illa said "now is not the time to relax measures", adding in a tweet that the "behaviour of minority groups is unacceptable".
Despite the many restrictions imposed in Spain since July, when the number of cases began rising again, infections have spiralled.
The health ministry on Friday reported 25,595 new confirmed cases -- the largest one-day jump of the second wave of the pandemic. The virus has so far killed more than 35,000 people in Spain and infected more than 1.1 million.