Catalonia's referendum on independence is under way, as voters across the region cast their ballots on the question: "Do you want Catalonia to become an independent state in the form of a republic?"

Since polls opened at 07:00 GMT, there have been frequent confrontations between Spanish police forces and would-be Catalan voters.

More than 460 civilians and up to 12 security officials have sustained injuries as a result, according to Ada Colau, the Mayor of Barcelona, and the Spanish Ministry of the Interior.

On social media, the exchange of opinions on the referendum also mirrored the tension in the streets of Catalonia.

Over 460 people injured in Catalonia already. As Mayor of BCN I demand an immediate end to police charges against the defenceless population https://t.co/412z6Jacap — Ada Colau (@AdaColau) October 1, 2017

Por el momento,9 agentes de @policia y 3de @guardiacivil han resultado heridos mientras cumplían la orden de la jueza del TSJC#EstamosporTI — Ministerio Interior (@interiorgob) October 1, 2017

Reactions in Spain were divided, with officials from the central government and regional government offering different versions of events.

Juan Ignacio Zoido, Spain's interior minister, praised the response of security officials as "proportional and professional" in a post containing a video showing a Spanish police officer providing a helping hand to a father and child near the Catalonian city of Girona.

Proporcionalidad y profesionalidad. Así actúan la @guardiacivil y la @policia, como este agente dialogando con un padre. #EstamosporTI pic.twitter.com/TX54CDjfJy — Juan Ignacio Zoido (@zoidoJI) October 1, 2017

However, Raül Romeva i Rueda, the Catalan government's minister of foreign affairs, took a different view on events. He criticised Madrid's response to the referendum, saying Catalonia would continue to push forward with the vote.

The Spanish govt has shown us their arguments: repression & violence. We will continue to show ours: ballot boxes, votes, democracy & peace. pic.twitter.com/upxb4p87q8 — Raül Romeva i Rueda (@raulromeva) October 1, 2017

The Spanish Ministry of the Interior posted a video showing stones being thrown at the Spanish Civil Guard, declaring "violence against the police continues".

Continúa la violencia contra los agentes. @guardiacivil se retira expeditivamente bajo una lluvia de piedras lanzadas en grupo#EstamosporTI pic.twitter.com/wQsL5hMsL1 — Ministerio Interior (@interiorgob) October 1, 2017

Spain's Civil Guard also posted a video showing clashes with members of the public, claiming officials were continuing to "resist harassment and provocations as they discharge their obligations proportionally in defence of the law".

La Guardia Civil resiste el acoso y las provocaciones ejerciendo con proporcionalidad sus funciones en defensa de la Ley#EstamosporTI pic.twitter.com/7ztW5NupEW — Guardia Civil (@guardiacivil) October 1, 2017

A number of individuals in Catalonia took to social media to contest the Spanish government's claims of proportionality, claiming violence was being used by security officials to deter Catalans from exercising their opinion.

Natza Farre's post, with images courtesy of Jordi Folch, showed police striking a number of civilians in the Guinardo district of Barcelona.

així ens han tractat al cap guinardó. imatges de jordi folch pic.twitter.com/q35tOc5n1u — natza farré (@natzafarre) October 1, 2017

Luz Sanchis, a journalist on the scene in Barcelona, posted the following video displaying police forcefully removing civilians from a polling centre at the Institute Pau Claris in Barcelona.

En el instituto Pau Claris, ahora. Mi hermana llora y yo con ella desde Madrid. pic.twitter.com/USE5FHkPxA — Luz Sanchis (@LuzSanchis) October 1, 2017

Mirroring the feelings expressed by many who had been prevented from voting, or disturbed by the police presence, Pau Subira Zurita asked "where is democracy" in the following post.

Beyond Spanish borders, across Europe, a number of high-profile politicians commented on the situation via Twitter.

Jeremy Corbyn, the leader of Britain's Labour Party criticised authorities for allowing "shocking" acts of violence to take place.

Police violence against citizens in #Catalonia is shocking. The Spanish government must act to end it now. — Jeremy Corbyn (@jeremycorbyn) October 1, 2017

Miro Cerar, centrist Slovenian leader, implored with officials involved to negotiate a peaceful resolution to the situation.

I am concerned about situation. I call for political dialogue, rule of law and peaceful solutions. #CatalanReferandum #Spain — dr. Miro Cerar (@MiroCerar) October 1, 2017

Charles Michel, Belgium's prime minister, also spoke out against the use of force by Spanish police. He called on both parties to resolve their political differences through non-violent means.

Violence can never be the answer! We condemn all forms of violence and reaffirm our call for political dialogue #CatalanReferendum #Spain — Charles Michel (@CharlesMichel) October 1, 2017

As the situation continues to develop, the eyes of the world seem to be increasingly focused on Catalonia and the Spanish government's actions.

Human Rights Watch, a US-based international NGO, has called for officials in Spain to respect the people of Catalonia's rights to "peaceful assembly and free expression", for both "those who oppose independence and those who support it".