Barcelona, Spain – Tens of thousands of demonstrators took to the streets of Barcelona on Thursday to celebrate and show support for a united Spain during the country's national day.

The rally comes at a tense time in the relationship between Madrid and the Catalan regional government, which has soured since the disputed October 1 independence referendum and subsequent fallout.

Catalan President Carles Puigdemont declared independence for eight seconds Tuesday night before suspending the declaration in favour of talks with the Spanish government.

Maria Garcia Anton, a 23-year-old student who attended the rally, told Al Jazeera: "Spain is one country and Catalonia is a part of it. The problems can be solved, but our country should remain intact."

Some are questioning the Spanish government's methods to keep the country together.

The Civil Guard, a military force charged with police duties, used "excessive force" to stop Catalans from voting on independence from Spain in the October 1 referendum, according to rights group Human Rights Watch (HRW).

Images and videos showing assaults on peaceful protesters and voters young and old went viral. However, the military police force was popular with demonstrators.

They chanted "Long live the Civil Guard", among other pro-union slogans.

"It was justified," Garcia said as she marched. "The court ruled the referendum was illegal and the Civil Guard did what was necessary."

Travel concerns

The Spanish High Court decided that the referendum contravened the nation's constitution and ordered police to stop it from occurring, while simultaneously requiring law enforcement to respect coexistence between citizens.

By the end of the day, almost 900 people had been injured by the authorities, according to an estimate from the Catalan Department of Health. The Spanish government insists that police acted lawfully and respectfully.

"The police may well have had the law on their side to enforce a court order, but it didn't give them the right to use violence against peaceful protesters," Kartik Raj, HRW's Western Europe researcher, said in a press release.

Raj wants an independent investigation to get to the bottom of HRW's findings, which include various tales of wounded protesters, including evidence that police allegedly broke the wrist of a 70-year-old woman.

But police violence was not on everyone's mind at the rally.

Jorge Puyol, an unemployed 31-year-old who told Al Jazeera his mother is Spanish and his father Catalan, said that he was worried about losing the rights afforded to citizens of the European Union, such as passport-free travel to other EU nations.

Scholars and politicians are not sure what exactly would happen if Catalonia were to secede, but it is known that the newly-formed state would have to apply for EU membership.

During the application process, treaties could be made to re-instate freedom of movement and trade. However, Spain would have to agree to allow for Catalonia's full membership.

Puyol is not sure that would happen.

Spanish Prime Minister Mariano Rajoy has taken a firm stance on Catalonia, giving Catalan President Puigdemont an ultimatum to clear up whether or not he declared independence by Monday.

If Puigdemont affirms the declaration, Rajoy promises to employ Article 155 of the Spanish constitution, which would allow Madrid to take control of Catalonia's government.

Although it is conceivable that Catalonia could still attain independence after Article 155 is invoked, Puyol would rather not live through such a divisive time.

"I have family in the rest of Spain and I like being able to travel without a passport. I don't want to risk these things," he said as he marched in Plaza Catalunya, one of Barcelona's main squares.

There, Puyol joined the crowd of thousands as police helicopters circled overhead, chanting "We won't be fooled, Catalonia is Spain!"