The UK's Foreign Office has failed to condemn the violent scenes in Catalonia as police launched a brutal crackdown on the region's peaceful attempt to hold an independence referendum.

More than 460 people have been injured as police baton-charged and fired rubber bullets to disperse crowds in Barcelona and other towns and cities. Barcelona's mayor Ada Colau demanded "an immediate end to police charges against the defenceless population".

Videos have showed police beating people repeatedly as they try to confiscate ballots and ballot boxes.

But when the Foreign Office finally put out a statement it failed to even mention, let alone condemn, the violence.

READ MORE: Voting closes in Catalonia after shameful day of violence by Spanish police leaves 761 people injured

A Foreign Office spokeswoman said: "The referendum is a matter for the Spanish government and people.

"We want to see Spanish law and the Spanish constitution respected and the rule of law upheld.

"Spain is a close ally and a good friend, whose strength and unity matters to us."

First Minister Nicola Sturgeon slammed the UK's response. She tweeted: "Statement from @foreignoffice on #Catalonia is shamefully weak. A true friend of Spain would tell them today’s actions wrong and damaging."

READ MORE: More than 1000 Scots gather to show support for Catalonia

Earlier, she called on the Spanish government to "change course" and let people "vote peacefully".

Sturgeon expressed her concerns on Twitter, stating: "Some of the scenes in #Catalonia this morning are quite shocking and surely unnecessary. Just let people vote."

She added: "Increasingly concerned by images from #Catalonia.

"Regardless of views on independence, we should all condemn the scenes being witnessed and call on Spain to change course before someone is seriously hurt. Let people vote peacefully."

Jeremy Corbyn earlier called Theresa May to intervene with the Spanish government.

The Labour leader condemned the "shocking police violence" being used as he insisted the Prime Minister contact her Spanish counterpart Mariano Rajoy over the situation.

He tweeted: "I urge Theresa May to appeal directly to Rajoy to end police violence in Catalonia & find political solution to this constitutional crisis."

Liberal Democrat leader Sir Vince Cable insisted Foreign Secretary Boris Johnson should call in the Spanish ambassador and tell him that the police response was "unacceptable".

Sir Vince said: "Police in a democracy should never drag people violently out of polling stations, whatever the arguments for or against holding a referendum. The police response looks to have been brutal and completely disproportionate.

"The Foreign Secretary should break off from conspiring against the Prime Minister and call in the Spanish ambassador to tell him that this is completely unacceptable."