The world's largest phone show opened in Barcelona on Monday with a visit by King Felipe VI as tensions run high just months after Catalonia's failed bid to break from Spain.
The king, a divisive figure in the northeastern region since he made a stern speech in October denouncing the secession attempt by Catalan leaders, toured the Mobile World Congress (MWC) accompanied by Barcelona Mayor Ada Colau and other officials.
But on Sunday evening, small pro- and anti-monarchy protests hit the Mediterranean city during an inaugural ceremony for the MWC, an annual event of high importance for Spain both financially and for its image.
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During the ceremony, Colau and regional parliament speaker Roger Torrent, a separatist, refused to follow protocol and officially welcome the king.
On her Facebook page, Colau -- who is not a separatist -- said she did not welcome the king because of his October speech, which came just days after a banned independence referendum was marred by police violence.
"The king didn't make even the smallest gesture of empathy towards people who suffered... and made a hardline speech endorsing the repressive line instead of trying to ease the conflict and bring serenity, as expected of a head of state," Colau wrote.
The failed bid to break from Spain brought huge uncertainty to the northeastern region, with more than 3,000 companies moving their legal headquarters out of Catalonia.
At the time, there had even been speculation that this year's MWC would be delayed with organisers saying they were "continuing to monitor developments" in Catalonia's secession crisis.
Following a declaration of independence by regional leaders on October 27, Madrid imposed direct rule on Catalonia, sacked its separatist government, dissolved its parliament and called snap regional elections.
Separatists once again won a majority in the December polls but they are currently struggling to form a regional government, with deposed Catalan president Carles Puigdemont in self-exile in Belgium and other separatist leaders in jail over the independence bid.
In Barcelona, independence supporters went to the airport to welcome participants in the global congress with signs reading "Shame on Europe," referring to the European Union's support for the government of Prime Minister Mariano Rajoy.
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Some 108,000 people are expected to visit the MWC this year, with organisers predicting the event will have an economic impact on Barcelona and its surroundings of 471 million euros ($581 million).
"The MWC is the showcase for major technological change in the world," said Spain's Tourism Minister Alvaro Nadal on Monday.
"We have to take care of its image."
In the congress centre hosting the MWC under intense police security, visitors will discover the latest technological progress, in particular, the hugely-anticipated 5G, or fifth generation mobile networks.
Eye-catching gadgets such as headsets that claim to help you lose weight without dieting and a smart meat thermometer are also on display.
High-profile executives such as World Bank president Jim Yong Kim will also attend, as will carmakers like Ford and BMW and aerospace giant Airbus.